1.88 g
Explanation:We are given;
Mass of a radioactive sample of Uranium as 30.0 g Half life of Uranium sample is 12 hoursTime is 2 daysWe are required to determine the amount of uranium left after 2 days
We are going to use the formula;N = N₀ × 0.5^n
Where, N is the remaining mass, N₀ is the original mass and n is the number of half lives.
n = (2 × 24) ÷ 12 hours
= 4
Therefore;
Remaining mass, N = 30.0 g × 0.5^4
= 1.875 g
= 1.88 g
Therefore, the mass of the remaining sample after decay is 1.88 g
What is a triple bond?
O
A. Single bonds made by 1 atom to 3 other atoms within a molecule
O
B. A covalent bond between 2 atoms where each atom contributes 6
electrons
O
C. An ionic bond between 2 atoms where 3 electrons have been
transferred
O
D. A covalent bond between 2 atoms where each atom contributes 3
electrons
The covalent bond between 2 atoms where each atom contribute 3 electrons is called a triple bond. In a triple bond, two are pi bonds and one is a sigma bond.
What is covalent bond ?Covalent bonds are formed between two non-metals through sharing of electrons. Two electron deficient atoms shares their valence electrons each other to achieve octet and forms covalent bonds.
Covalent bonds can be single, double or triple bonds. Single bonds are sigma bonds. Double bonds are formed through one sigma bond and one pi bond formed through sideways overlapping.
In a single bond each atoms shares one electron. In double bond each atom shares two electrons and in triple bonds, 3 electrons are shared by each atom. Hence, option D is correct.
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2. _ NaCl + _ AgNO3 → _NaNO3 + __Agci
Answer: Its already balanced.
Explanation:
________ is formed when water boils.
a. Gas
b. Steam
c. Plasma
Answer:
answer is b
Explanation:
when you boil water steam come from the pan
How many molecules are in each of the following compounds or elements?
3) 9.273 x 10^7 grams of chromium (III) bicarbonate
Answer:
0.241 × 10³⁰ molecules
Explanation:
Given data:
Mass of Cr(HCO₃)₃ = 9.273 × 10⁷ g
Number of molecules = ?
Solution:
Number of moles = 9.273 × 10⁷ g/ 235 g/mol
Number of moles = 0.04× 10⁷ mol
The given problem will solve by using Avogadro number.
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.
The number 6.022 × 10²³ is called Avogadro number.
For example,
18 g of water = 1 mole = 6.022 × 10²³ molecules of water
1.008 g of hydrogen = 1 mole = 6.022 × 10²³ atoms of hydrogen
For 0.04× 10⁷ moles of Cr(HCO₃)₃:
0.04× 10⁷ moles × 6.022 × 10²³ molecules / 1 mol
0.241 × 10³⁰ molecules
Question 1: Which of the following is an example of an exothermic chemical reaction?
A. raw dough absorbs heat from the oven and bakes, creating a new substance: bread.
B. a cake is cut into slices
C. Liquid water is heated and turns to steam.
D. a firework explodes in the sky and releases heat and light.
Answer:
the answer is D
Explanation:
the reason how ik this is that i already did this test so yea
The example of an exothermic reaction among the provided options is D, where a firework explodes and releases both heat and light, a hallmark of exothermic processes.
Explanation:An exothermic chemical reaction is a process that releases energy in the form of heat or light. When chemical bonds are formed in a new substance, energy is generally released, indicating an exothermic process. Among the options given, option D, where a firework explodes in the sky and releases heat and light, is a classic example of an exothermic reaction. This option perfectly illustrates the concept as fireworks, upon detonation, release energy in the form of heat and light due to the combustion reactions occurring within them. This reaction releases energy in the form of heat and light, making it an exothermic reaction. Exothermic reactions involve the release of energy, while endothermic reactions involve the absorption of energy.
1. (5) Solid nickel reacts with aqueous nitric acid (HNO3) to form aqueous nickel (III) nitrate and
hydrogen gas. Write out and balance the chemical equation, including phases.
2. (5) What type of reaction is this? Can it undergo redox? If so, write out the balanced half-
reactions
Answer:
See every answer with its explanation below
Explanation:
1. Write the molecular equation
Ni(s) + HNO₃ (aq) → Ni(NO₃)₃ (aq) + H₂(g)↑ ↑ ↑ ↑
solid nickel aqueous nitric aqueous nickel(III) hydrogen gas
acid nitrate
2. Balance the molecular equation:
2Ni(s) + 6HNO₃ (aq) → 2 Ni(NO₃)₃ (aq) + 3H₂(g)
3. Type of reaction
This is a replacement reaction because the nickle is taking the place of hydrogen in the nitric acid and the hydrogen is released. It is also a redox reaction because nickel is being oxidized and hydrogen is being reduced.
The balanced half-reactions are:
Oxidation reaction:2Ni⁰ → 2Ni³⁺ + 2×(3e⁻)
Each nickle atom loses 3 electrons increasing its oxidation state from 0 to +3.
Reduction reaction:6H⁺ + 6e⁻ → 3H₂⁰
Each H⁺ gains 1 electron reducing its oxidation state from +1 to 0.
PLEASE HELP
Refer to the reactants of this synthesis reaction.
_[blank]_Mg + _[blank]_O2 → ?
What completed equation shows the product formed?
4Mg + O2 → 2Mg2O
Mg + O2 → MgO2
2Mg + O2 → 2MgO
2Mg + O2 → Mg2O2
2 Mg + O₂ → 2 MgO
Explanation:
Metallic magnesium (Mg) will react with gaseous oxygen (O₂) to produce solid magnesium oxide (MgO).
2 Mg + O₂ → 2 MgO
To balance the chemical equation the number of atoms of each element entering the reaction have to be equal to the number of atoms of each element leaving the reaction, in order to conserve the mass.
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Elias observed a sample in the classroom. The sample was a liquid at room temperature. He performed a conductivity test and found that it did not conduct electricity. Which classification would best fit the sample?
A) ionic
B) metal
C) nonmetal
D) salt
Answer:
C) nonmetal
Explanation:
Given;
The sample is in liquid state and do not conduct electricity.
We have given four types of classification.So for first,
A) Ionic
Ionic compounds are found in solid state at room temperature and it conducts electricity when dissolved in water. Hence the sample could not be ionic.
B)Metal
Metals are found in solid state at room temperature except mercury and it conducts electricity very well. Mercury also conducts electricity.So the sample is not a metal.
C)Nonmetal
Non metals are found in solid state except bromine which is in liquid state at room temperature and it does not conducts electricity.
Here the property of nonmetal matches with the sample, so the sample is a nonmetal and it could be Bromine.
D)Salt
Salt is an ionic compound found in solid state at room temperature and it conducts electricity when dissolved in water. Hence the sample could not be salt.
Answer:
C for k12
Explanation:
Consider the redox reaction below.
Zn(s) + 2HCl(aq) —
ZnCl2(aq) + H2(g)
Which half reaction correctly describes the oxidation that is taking place?
Zn2+ (s) + 2e(aq)>Zn(s)
Zn(s) —»Zn2+(aq) + 2e-
2H+ + 2e-->H2
H2+2e--> 2H+
Answer:
Zn(s) → Zn⁺²(aq) + 2e⁻
Explanation:
Let us consider the complete redox reaction:
Zn(s) + 2HCl(aq) → ZnCl₂(aq) + H₂(g)
This is a redox reaction because, both oxidation and reduction is simultaneously taking place.
Oxidation (loss of electrons or increase in the oxidation state of entity)Reduction (gain of electrons or decrease in the oxidation state of the entity)An element undergoes oxidation or reduction in order to achieve a stable configuration. It can be an octet configuration. An octet configuration is that of outer shell configuration of noble gas.Here Zn(s) is undergoing oxidation from OS 0 to +2
And H in HCl (aq) is undergoing reduction from OS +1 to 0.
Therefore, for this reaction;
Oxidation Half equation is:
Zn(s) → Zn⁺²(aq) + 2e⁻
Reduction Half equation is:
2H⁺ + 2e⁻ → H₂(g)
Final answer:
The correct oxidation half-reaction for the reaction of zinc with hydrochloric acid is Zn(s) → [tex]Zn^2^+(aq) + 2e^-[/tex] Zinc is oxidized by losing two electrons to form zinc ions.
Explanation:
The oxidation half-reaction in the chemical reaction involving zinc and hydrochloric acid is represented by the equation:
Zn(s) → [tex]Zn^2^+(aq) + 2e^-[/tex]
This equation indicates that zinc metal (Zn) is losing two electrons, thus being oxidized to zinc ions ([tex]Zn^2^+[/tex]), which go into solution. The loss of electrons is shown by the electrons being products in this half-reaction. The correct choice for the oxidation half-reaction in the provided list is Zn(s) → [tex]Zn^2^+(aq) + 2e^-[/tex].
The following are examples of chemical properties except ____.
Choices
the ability to burn
the ability to be crushed
the ability to react with oxygen
toxicity
The ability to be crushed is a physical property and therefore is the answer.
Answer:
the ability to be crushed
Explanation:
Chemical change are effects that is accompanied by changes in the chemical composition of a substance. When chemical changes occur the new substance are chemically different from the formal substance. A new chemical matter is usually formed after the change occur . Example of chemical changes are rusting of iron, toxicity, combustion(substance burning in the presence of oxygen), ability of substance to react with oxygen.
Physical changes are changes that does not alter the chemical composition of the new substance . Example of physical changes are steam condensing into liquid, sugar dissolving in water and crushing a solid substance. The changes are usually physical changes. The overall substance does not change in chemical composition.
The density of 300 mL of water was determined, and then 15 grams of sodium nitrate was dissolved in the water. The student determined the density of the aqueous solution and recorded the collected data in a table. The sodium nitrate in this investigation is
a. the solute
b. undergoing chemical change
c. the solvent
d. changing from a solid to a gas
Answer:
the sodium nitrate in this investigation is
a) the solute
b) undergoing chemical change
Explanation:generally, solute is the substance which is added in solvent.
The substance which is taken in relatively more volume is the solvent.
so, here sodium nitrate (NaNO₃) is the solute which is dissolved in water (H₂O) , which is solvent.
The reaction between them is :
NaNO₃ + H₂O ⇒ Na⁺ (aq) + NO₃⁻ (aq) ; (aq) denotes aqueous;
so, here sodium nitrate undergoes chemical change into aqueous sodium ions(Na⁺) and aqueous nitrate ions(NO₃⁻).
Pb(NO3)2 + K2CO3 --> PbCO3 + KNO3
A. 5
B. 2
C.
4
Answer:
Pb(NO3)2 + K2CO3 ----> PbCO3 + 2KNO3
The answer is B. 2
Hope this helps!
What does adding a neutron to an atom's nucleus do to the atom's mass?
O
A. It adds 1 more unit of mass to the atomic weight of the atom.
B. A proton will be added with the neutron, increasing the weight by 2
mass units.
C. A neutron has no mass, so the atomic mass will remain
unchanged.
O
D. Adding a neutron is balanced by adding an electron, keeping the
mass the same.
Answer:
A :) It adds 1 more unit of mass to the atomic weight of the atom.
Explanation:
I just completed it on apex
Answer:
A
Explanation:
3 What is the mass of 15.0 x1015 atoms of uranium?
Answer:
Mass = 595 × 10⁻⁸ g
Explanation:
Given data:
Number of atoms of uranium = 15.0 × 10¹⁵ atoms
Mass of uranium = ?
Solution:
The given problem will solve by using Avogadro number.
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.
The number 6.022 × 10²³ is called Avogadro number.
For example,
1 mole of uranium = 6.022 × 10²³ atoms of uranium
1 mole × 15.0 × 10¹⁵ atoms / 6.022 × 10²³ atoms of uranium
2.5 × 10⁻⁸ moles
Mass of uranium:
Mass = number of moles × molar mass
Mass = 2.5 × 10⁻⁸ moles × 238 g/mol
Mass = 595 × 10⁻⁸ g
Gases fill up any available space as they don't have a definite shape.
a. True
b. False
Answer:
Particles are far apart from each other because there are very weak forces of attraction between them. They move fast in all directions. Because of this, gases don't have a definite shape or volume and fill any container. Because there is lots of free space between particles, gases can easily be compressed.
Explanation:
Practice 14
The mass of a proton is approximately
1) 1/2000 times the mass of a neutron and a unit positive charge
2) 1/2000 times the mass of a neutron and a unit negative charge
3) 2000 times the mass of an electron and a unit positive charge
4) 2000 times the mass of an electron and a unit negative charge
Answer:
3) 2000 times the mass of an electron and a unit positive charge
Explanation:
The proton is approximately 2000 times massive than electron.
Neutron and proton are present inside the nucleus. Proton has positive charge while neutron is electrically neutral. Proton is discovered by Rutherford while neutron is discovered by James Chadwick in 1932.
Symbol of proton= P+
Symbol of neutron= n0
Mass of proton=1.672623×10-27 Kg
Mass of neutron=1.674929×10-27 Kg
An atom consist of electron, protons and neutrons. Protons and neutrons are present with in nucleus while the electrons are present out side the nucleus.
The electron is subatomic particle that revolve around outside the nucleus and has negligible mass. It has a negative charge.
Symbol= e-
Mass= 9.10938356×10-31 Kg
It was discovered by j. j. Thomson in 1897 during the study of cathode ray properties.
To what temperature in kelvin will a 2.3 L balloon have to be heated to expand to a volume of 400 L Assume the initial temperature of the balloon is 25 degrees celsius.
Answer:
T₂ = 51826.1 K
Explanation:
Given data:
Initial Volume = 2.3 L
Final volume = 400 L
Initial temperature = 25 °C (25+ 273 = 298 K)
Final temperature = ?
Solution:
V₁/T₁ = V₂/T₂
T₂ = V₂ T₁/V₁
T₂ = 400 L . 298 K / 2.3 L
T₂ = 119200 K. L / 2.3 L
T₂ = 51826.1 K
To find the temperature in Kelvin for a balloon to expand, we can use Charles's Law. Converting the initial temperature of 25 degrees Celsius to Kelvin gives us 298 K. By setting up the equation, we find that the balloon needs to be heated to approximately 5172.17 K.
Explanation:To find the temperature in Kelvin at which a 2.3 L balloon expands to a volume of 400 L, we can use Charles's Law. Converting the initial temperature of 25 degrees Celsius to Kelvin gives us 298 K. Setting up the equation, we have:
V₁ / T₁ = V₂ / T₂
Substituting the given values, we have:
2.3 L / 298 K = 400 L / T₂
Cross multiplying and solving for T₂, we find:
T₂ = (400 L * 298 K) / 2.3 L = 5172.1739 K
Therefore, the balloon will need to be heated to approximately 5172.17 K in order to expand to a volume of 400 L.
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Since the new oceanic crust is created at the mid-ocean ridges, then the Earth is getting bigger.
True
False
Answer:
False
Explanation:
It is true that new crust is being created at the mid-oceanic ridges, but this does not make the Earth any bigger despite the the growth of oceanic crusts in these regions.
The reason that Earth does not get bigger is because the same plates that are being created at the divergent plate boundaries are recycled into the mantle at the subduction zones. Because of this, the surface area of the Earth remains the same.
A mixture formed of isopropyl alcohol C,H,OH (70%) and water (30%), if you know
that the density of the mixture (at 20°C) = 0.79 g/mL, Calculate :
(1) Molar concentration.
(2) Molal concentration. (C=12 ,H=1 ,O=16 )
Answer:
(1) C C3H7OH = 9.200 M
(2) C C3H7OH = 11.647 m
Explanation:
mixture:
∴ 70% = (g C3H7OH/g mix)×100
∴ 30% = (gH2O/g mix)×100
∴ δ mix = 0.79 g/mL
assuming:
g mix = 100g = 0.100 Kg⇒ V mix = (100g)×(mL/0.79g) = 126.582 mL mix = 0.1266 L mix
⇒ g C3H7OH = 70g
⇒ g H2O = 30g
∴ Mw C3H7OH = 60.1 g/mol
∴ Mw H2O = 18 g/mol
(1) Molar concentration (M):
M ≡ mol solute/L mix⇒ C C3H7OH = ((70 g)(mol/60.1 g))/(0.1266L) = 9.200 M
(2) molal concentration (m):
m ≡ mol solute/Kg mix⇒ C C3H7OH = ((70 g)(mol/60.1g))/(0.100 Kg) = 11.647 m
the values are given in the table below
Substance ΔH°f (kJ/mol)
SO2 (g) −297
SO3 (g) −396
SO2Cl2 (g) −364
H2SO4 (ℓ) −814
H2O (ℓ) −286
The value of ΔH° for the following reaction is −62.1 kJ. What is the value of ΔH°f for HCl(g)?
SO2Cl2(g) + 2 H2O(ℓ)→ H2SO4(ℓ) + 2 HCl(g)
The enthalpy change for the given reaction is -62.1 kJ. By applying Hess's Law, we can calculate the enthalpy of formation (ΔH°f) for HCl(g). Using the given enthalpy values, we find that ΔH°f for HCl(g) is -62 kJ/mol.
Explanation:The reaction given is:
SO2Cl2(g) + 2 H2O(ℓ) → H2SO4(ℓ) + 2 HCl(g)
We know that the enthalpy change, ΔH°, for the reaction is -62.1 kJ. We can use the given enthalpy of formation (ΔH°f) values to calculate the enthalpy of formation of HCl(g).
Calculate the enthalpy change for the formation of H2SO4(ℓ) from its elements (ΔH°f H2SO4(ℓ)). Calculate the enthalpy change for the formation of SO2Cl2(g) from its elements (ΔH°f SO2Cl2(g)). Calculate the enthalpy change for the formation of HCl(g) from its elements (ΔH°f HCl(g)).
By applying the Hess's Law, we can determine the enthalpy changes based on the given data.
ΔH°f HCl(g) = ΔH°f SO2Cl2(g) + ΔH°f H2SO4(ℓ) - 2ΔH°f H2O(ℓ)
Substituting the given values, we have: ΔH°f HCl(g) = -364 kJ/mol + (-814 kJ/mol) - 2(-286 kJ/mol) = -62 kJ/mol
Therefore, the value of ΔH°f for HCl(g) is -62 kJ/mol.
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The heat of formation, or ΔH°f, for hydrogen chloride (HCl(g)) is −92.3 kJ/mol. This was found using Hess's Law and the given standard heats of formation.
Explanation:The question is asking us to determine the heat of formation, or ΔH°f, for hydrogen chloride (HCl(g)) using the provided standard heats of formation and the heat of the reaction. This falls under the topic of thermodynamics in chemistry.
According to Hess's Law, the total enthalpy change for a reaction is the sum of the enthalpy changes for each step, regardless of the number of steps. So, the ΔH° for the reaction is the sum of the heats of formation of the products minus the sum of the heats of formation of the reactants. Mathematically, that's ΔH° = [ΔH°f(H2SO4) + 2*ΔH°f(HCl)] - [ΔH°f(SO2Cl2) + 2*ΔH°f(H2O)].
The only unknown in this equation is ΔH°f(HCl), which we can solve for:
ΔH°f(HCl) = {[ΔH° + ΔH°f(SO2Cl2) + 2*ΔH°f(H2O)] - ΔH°f(H2SO4)} / 2. Substituting the given values into this equation gives ΔH°f(HCl) = {-62.1 kJ + (-364 kJ) + 2*(-286 kJ) - (-814 kJ)} / 2 = −92.3 kJ/mol. So, the heat of formation for HCl(g) is −92.3 kJ/mol.
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9. I've been called a "storage tank" by those with little taste. I'm a sac filled with water, food,
enzymes, or waste.
Answer:
central vacuole
Explanation:
pls answer
Maria is baking cookies. She mixes water, flour, sugar, baking powder, butter and chocolate chips and then measures the mass of her ingredients. The mixture has a mass of 1053 grams. Maria baked the cookies for 15 minutes and then measured the mass of the cookies and found they now had a mass of 845 grams. Why didn't the cookies obey the law of conservation of mass?
Group of answer choices
The law of conservation of mass was not obeyed since Maria did not measure the mass of all of the ingredients.
The law of conservation of mass was not obeyed since some of the mass was destroyed in the baking process.
The law of conservation of mass was obeyed since some of the mass evaporated while the cookies were baking.
The law of conservation of mass was not obeyed since some of the mass was destroyed in the oven.
Answer:
The law of conservation of mass was obeyed since some of the mass evaporated while the cookies were baking.Explanation:
The law of conservation of mass, as other physic's laws, is universal, meaning that it is obeyed in any circumstance, place, and time.
Thus, any explanation that asserts that the law of conservation of mass is not obeyed must be discarded.
Hence, first, second and fourth options are incorrect.
The law of conservation of mass states that during any physical or chemical process the mass of the substances can neither created nor destroyed; then, what happened that made the mass of the mixture of ingredients mixed by Maria (1053 g) were greater than the mass of the cookies baked for 15 minutes (845 g)?
One of the physical process that occurs when cooking, due to the increase of temperature, is the evaporation of water (besides the chemical reactions between the ingredients, some of which produce other gases).
The water in form of vapor (steam) will "escape" from the mass and the oven, so when the cookies are weighted they will weight less than the mixture, because the water was transformed from liquid state to gas state; i.e. some of the mass evaporated while the cookies were baking. Thus, the third choice is correct.
The area of the circular base of a can of
dog food is 12.5 in. The can is 6 inches
high. What is its volume?
The volume of the can of dog food is approximately 74.8 cubic inches.
To calculate the volume of the can of dog food, we use the formula for the volume of a cylinder, which is V = (pi x [tex]r^2[/tex] x h), where V is the volume, pi is approximately 3.14159, r is the radius of the base, and h is the height of the cylinder.
First, we need to find the radius of the base. We know the area (A) of the circular base is 12.5 in2, and the area of a circle is given by A = pi x [tex]r^2[/tex]. We can solve for r:
A = pi x [tex]r^2[/tex]
12.5 = 3.14159 x [tex]r^2[/tex]
[tex]r^2[/tex] = 12.5 / 3.14159
[tex]r^2[/tex] = 3.981
r = [tex]\sqrt{3.981}[/tex]
r = 1.994 inches approximately.
Now that we have the radius, we can calculate the volume of the can:
V = pi x [tex]r^2[/tex] x h
V = 3.14159 x [tex](1.994 in)^2[/tex] x 6 in
V = 74.8 in3 (rounded to one decimal place).
Thus, the volume of the can of dog food is approximately 74.8 cubic inches.
5.000 g of Compound X with molecular formula C₄H₆ are burned in a constant-pressure calorimeter containing 25.00 kg of water at 25°C. The temperature of the water is observed to rise by 2.161 °C. (You may assume all the heat released by the reaction is absorbed by the water, and none by the calorimeter itself.) Calculate the standard heat of formation of Compound X at 25°C.round it to 3 significant digits.
Answer:
ΔHf = 305 kJ/molExplanation:
1. Amount of heat absorbed by the water
Q = m × C × ΔTWhere:
Q is the heat absorbed: to determinem is the mass of water: 25.00 kg = 25,000 gSpecific heat of water: 4.186 J/g °CΔT is the increase of the temperature: 2.161 ºCQ = 25,000 g × 4.186 J/gºC × 2.161 ºC = 226,148.65 J2. Standard heat of formation of compound X: ΔHf
ΔH rxn = ∑ΔHf (products) - ∑Δf (reactants)Reaction:
C₄H₆ (g) + 11/2 O₂ (g) → 4CO₂ (g) + 3H₂O (g)ΔHrxn = 4ΔHf CO₂ (g) + 3 ΔHf H₂O (g) - ΔHf C₄H₆(g) ΔHrxn = Q released in the reaction / number of moles of compound XQ released in the reaction = - Q absorbed by water = -226,148.65 Jnumber of moles = mass in grams / molar massmolar mass of C₄H₆ = 4 × 12.011 g/mol + 6 × 1.008 g/mol = 54.092 g/molnumber of moles = 5.000 g / 54.092 g/mol = 0.09243511 molΔHrxn = - 226,148.65 J / 0.09243511 mol = -2,446,566.55 J / molΔHrxn ≈ - 2,446 Kj / mol ≈ - 2,450 kJ / mol- 2,450 kJ/mol = 4ΔHf CO₂ (g) + 3 ΔHf H₂O (g) - ΔHf C₄H₆(g)From tables (at 25ºC):
ΔHf CO₂ (g) = - 393.5 kJ/molΔHf H₂O (g) = -241.8 kJ/mol- 2,450 kJ/mol = 4 (-393.5 kJ/mol) + 3 (-393.5 kJ/mol) - ΔHf C₄H₆
ΔHf C₄H₆ = 2,450 kJ/mol - 2,754.5 = 304.5 kJ/mol ≈ 305 kJ/mol
A chemist determined by measurements that 0.0450 moles of gold participated in a chemical reaction. Calculate the mass of gold that participated in the chemical reaction.
Be sure your answer has the correct number of significant digits.
Answer:
8.86 g
Explanation:
Molar mass gold = 196.97 g/mol
196.97 g/mol * 0.0450 mol ≈ 8.86 g
The mass of gold that participated in the chemical reaction is 8.86 g.
Molar mass gold = 196.97 g/mol
196.97 g/mol * 0.0450 mol ≈ 8.86 g
What are chemical reactions and examples?
A chemical reaction occurs when one or more chemicals are converted to one or more other chemicals. Example: Iron and oxygen combine to form rust. Vinegar and baking soda combine to form sodium acetate, carbon dioxide, and water.
A chemical reaction is a process in which one or more substances are present. H. Convert the reactants to one or more other substances d. H. The products are converted to each other to form new substances with properties different from the molecules of the reactants. This is called the product.
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this is a reaction And products are
Cu(s)+2AgNO3(aq)=> 2Ag(s)+Cu(NO3)2(aq)
Answer:
2Ag + Cu(NO3)2
Explanation:
A chemical reaction is represented by a chemical equation which show the reactant and products. Reactants are written on left side of arrow while products are written on right side. The number of atoms are remain same however arrangement of atoms is different on both side.
For example:
Cu(s) + 2AgNO3(aq) → 2Ag + Cu(NO3)2
In this reaction Cu and AgNO3 are reactants while Ag and Cu(NO3)2 are products.The number of atoms are same on both side however arrangement of atoms is different.
I. Determine the mass of reactants and products that will be needed if one mole of P4(s) reacts completely, as follows
P4(s) + 6 H2(g) →4 PH3(g)
II. What is the total mass of the reactants? What is the mass of the products?
III. What principle is illustrated by this example?
If someone could really help me with explanation as well thank you very much
Answer:
I. Reagents:
P₄= 123.88 g
H₂ = 12 g
Products:
PH₃= 135.88g
II. Total reagents = 135.88 g
Total products = 135.88 g
III. The principle of conservation of mass
Explanation:
I. First, the molar masses of all reagents and all reaction products are calculated:
• mP₄ = 4 x mP = 4 x 30.97g = 123.88 g / mol
• mH₂ = 2 x mH = 2 x 1.00g = 2 g / mol
• mPH₃ = 4 x mH + m P = 3 x 1.00g + 30.97g = 33.97 g / mol
Having the equation balanced, it can be seen that in order for one mole to react completely of P₄, 6 moles of H₂ must react, and 4 moles of PH₃ will be produced. With the molar masses, we obtain the reacting masses of each reagent and the mass of product that is formed:
Reagents:
P₄: 1 mol ≡ 123.88 g
H₂: 6 moles ≡ 12 g
Products:
PH₃: 4 moles ≡135.88g
II. We add the total mass of the reagents:
Total reagents = mP₄ + mH₂ = 123.88 g + 12 g = 135.88 g
As the reaction product is only PH₃, the total mass of products is 135.88 g
III. It is seen that the mass of reagents necessary to produce the reaction is equal to the mass of product obtained. Therefore, the principle illustrated with this example is the principle of conservation of mass, it says that “In an isolated system, during any ordinary chemical reaction, the total mass in the system remains constant, that is, the mass Consumption of reagents is equal to the mass of the products obtained ”
The mass of reactants (P4 and H2) and product (PH3) is calculated using their molar masses. The reactants have a total mass of 136 g and the product also has a total mass of 136 g, illustrating the law of conservation of mass.
Explanation:The chemical equation given is P4(s) + 6 H2(g) → 4 PH3(g). This equation tells us that one mole of P4 reacts with 6 moles of H2 to produce 4 moles of PH3.
Firstly, we need to find the molar masses of P4, H2, and PH3. Using the atomic mass of Phosphorus (P) = 31 g/mol and Hydrogen (H) = 1 g/mol, the molar mass of P4 would be 4*31 = 124 g/mol. The molar mass of H2 = 2*1 = 2 g/mol. And the molar mass of PH3 = 31 + 1*3 = 34 g/mol.
Then we can find the total mass of reactants and products: For reactants, one mole of P4 is 124 g and six moles of H2 is 6*2 = 12 g. So, the total mass of reactants is 124+12 = 136 g. For products, four moles of PH3 would be 4*34 = 136 g.
This example illustrates the law of conservation of mass, which states that matter cannot be created or destroyed in a chemical reaction. Thus, the total mass of the reactants is equal to the total mass of the products.
Learn more about Law of Conservation of Mass here:https://brainly.com/question/9391940
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The phenomenon of marble cancer is due to (a) soot particles (c) fog (b) CFCs (d) acid rain
Answer:
The phenomenon of marble cancer is due to (d) acid rain.
Explanation:
The marble cancer is the corrosion of the buildings and statues made up of marble due to the action of sulphuric acid and nitric acid.
[tex]SO_{2}[/tex] and [tex]NO_{x}[/tex] are produced due to pollution.
When these oxides mix with the rain drops in the cloud, they form sulphuric acid and nitric acid. When these acids come in contact with the marble, they cause corrosion.
Hence, acid rain causes the phenomenon of marble cancer.
Acids are described as corrosive because they a. turn litmus blue. b. taste bitter. c. “eat away” at other materials. d. feel slippery.
Answer:
C
Explanation:
acids are corrosive since they tend to destroy every single thing they do get a big example is the acidic rain which tends to corrode iron sheet thus making them to appear worn out and full of rust
Answer:
It's C.
Explanation:
c: eat away at other materials.
Sand is made up of silicon dioxide, SiO2 (molar mass=60.). How many silicon atoms are in a
smgle grain of sand weighing 55.2 micrograms?
Answer:
5.54 × 10¹⁷ atoms
Explanation:
Given data:
Mass of sand = 55.2 μg (55.2 ×10⁻⁶ g)
Molar mass of sand = 60 g/mol
Number of atoms = ?
Solution:
Number of moles = mass/ molar mass
Number of moles = 55.2 ×10⁻⁶ g / 60 g/mol
Number of moles = 0.92 × 10⁻⁶ mol
Number of atoms:
one mole = 6.022 × 10²³ atoms
0.92 × 10⁻⁶ mol × 6.022 × 10²³ atoms / 1mol
5.54 × 10¹⁷ atoms