That would be D Stoichiometry.
Answer:
d
Explanation:
At what time of day are dissolved oxygen levels most likely to be highest?
Answer:
It's C - 6:00PM.
Explanation:
A student is designing an experiment about the factors that affect math
grades. Which statement best represents a possible hypothesis for this
experiment?
Answer: B. If students spend at least 1 hour per night studying math, then they will get a grade of 85 or higher.
Explanation: A hypothesis is defined as a tentative or predictions or an educated guess of scientific questions. A hypothesis is always done before performing an experiment.
The correct hypothesis for the given experiment will be "If students spend at least 1 hour per night studying math, then they will get a grade of 85 or higher" because it has an if-then statement which is a conditional statement where statement after "if represents hypothesis" and "then represents conclusion".
Hence, the correct answer is "B. If students spend at least 1 hour per night studying math, then they will get a grade of 85 or higher."
A possible hypothesis for an experiment on factors affecting math grades could be: 'The amount of time spent studying directly affects math grades'. This hypothesis can be tested by tracking students' study times and their corresponding math grades.
Explanation:In designing an experiment about factors that affect math grades, a possible hypothesis could be: 'The amount of time spent studying directly affects math grades.' This hypothesis is testable and directly relates to the experiment's topic. You could set up an experiment where you track a group of students' math grades and measure the amount of time they dedicate to studying math. If those who study more have better math grades, your hypothesis would be supported.
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One major cause of flood is
Answer:
Localized flooding may be caused or exacerbated by drainage obstructions such as landslides, ice, debris, or beaver dams. Slow-rising floods most commonly occur in large rivers with large catchment areas. The increase in flow may be the result of sustained rainfall, rapid snow melt, monsoons, or tropical cyclones.
Explanation:
How much energy in Joules is released by burning a cheese ball that raises the temperature of
74.2 g water from 24°C to 41°C? How many Calories is this?
Answer:
1. The heat energy in Joules is 5280.22J
2. The heat energy in calories is 1261.4 calories
Explanation:
Step 1:
Data obtained from the question.
The following data were obtained from the question:
Mass of water (M) = 74.2 g
Initial temperature (T1) = 24°C
Final temperature (T2) = 41°C
Change in temperature (ΔT) = T2 - T1 = 41 - 24 = 17°C
Heat energy (Q) =?
Recall:
Specific heat capacity of water = 4.186 J/g°C
Step 2:
Determination of the energy in Joules.
This is illustrated below:
Q = MCΔT
Q = 74.2 x 4.186 x 17
Q = 5280.22J
Step 3:
Conversion of the heat energy in Joules to calories. This is illustrated below:
4.186 J = 1 calorie
Therefore, 5280.22J = 5280.22/4.186 = 1261.4 calories
Directions: The solubility curve for several common salts is shown in the graph. Use the graph to answer any questions that follow.
A KNO3 solution hits saturation when 75 g of salt have dissolved. At which temperature is the solution?
A.
15°C
B.
25°C
C.
45°C
D.
55°C
The saturation of a KNO3 solution at 75g corresponds to the temperature on the solubility curve where 75g aligns with, in this case purported as 25°C (Option B).
Explanation:To answer the question regarding the saturation of a KNO3 solution, you'd want to align the given quantity, 75g, on the y-axis (representing salt dissolved) with the corresponding temperature on the x-axis of the solubility curve. As the exact graph isn't provided within the question, let's assume that 75g of KNO3 aligns with 25°C. This would mean that a KNO3 solution hits saturation at 75g at 25°C, thus the answer would be B (25°C). Remember that the solubility of a substance increases with temperature, thereby allowing more salt to dissolve.
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Select the correct answer.
The chemical composition of most stars usually has which element in the highest concentration?
A. oxygen
B. hydrogen
OC. chromium
OD. lead
Answer:
B. Hydrogen
Explanation:
Answer:
B. Hydrogen
Explanation:
The most abundant gas is hydrogen which is fuel used by stars to create energy.
Molecules _____.
A) are named according to the alphabet
B) are the smallest units of matter
C) must be made of two different elements
D) are made of two or more atoms
Answer:
D
Explanation:
A is incorrect because they are named by elements and the number of atoms.
B is incorrect because the smallest units of matter are usually considered to be atoms.
C is incorrect because O2 is considered a molecule, and is made of only one element.
So, D is correct, because molecules are groups of two or more atoms that are held together by chemical bonds.
Answer:
D
Explanation:
Summarize a paragraph of what you’ve learned about mile carnival
A description of the solar system in which all the planets revolve around
the sun is called
What is the molality of 49 grams of NaCl in 469 grams of H2O (water)
Answer : The molality of sodium chloride is, 1.79 m
Explanation :
To calculate the molality of solution, we use the equation:
[tex]\text{Molality}=\frac{m_{solute}\times 1000}{M_{solute}\times W_{solvent}\text{ (in grams)}}[/tex]
Where,
[tex]m_{solute}[/tex] = Given mass of solute (sodium chloride) = 49 g
[tex]M_{solute}[/tex] = Molar mass of solute (sodium chloride) = 58.5 g/mol
[tex]W_{solvent}[/tex] = Mass of solvent (water) = 469 g
Now put all the given values in above equation, we get:
[tex]\text{Molality of }NaCl=\frac{49g\times 1000}{58.5g/mol\times 469kg}\\\\\text{Molality of }NaCl=1.79mol/kg=1.79m[/tex]
Hence, the molality of sodium chloride is, 1.79 m
5. Which are generally less soluble, compounds with chlorate ions or carbonate ions?
Answer:
Compounds with Carbonate ions are less soluble than the compounds with Chlorate ions.
Explanation:
The reason is that the compounds with carbonate ions have less attraction between positive and negative charges. (Solvation)
liters of a 2.40 M
M
KBr
K
B
r
solution to obtain 3.40 moles of KBr
Answer:
1.42 L
Explanation:
Step 1:
The following data were obtained from the question :
Molarity of KBr = 2.40 M
Mole of KBr = 3.40 moles
Volume of solution =?
Step 2:
Determination of the volume of the solution.
Molarity of solution is simply the mole of the solute per unit volume the of solution. It is given as :
Molarity = mole /Volume
Volume = mole /Molarity
Volume = 3.4/2.4
Volume = 1.42 L
Therefore, the volume of the solution is 1.42 L
What is an element?
a. A substance that is made of water.
b. A substance made of only one type of atom.
c. A substance that is made of no atoms.
d. A substance made of more than one type of atom.
Answer:
b. a substance made of only one type of atom
Explanation:
Elements are what you find on the periodic table of elements.
Take oxygen, for example. You can have one or multiple atoms, but if they are all oxygen atoms it's an element.
"a" is incorrect because water is not an element, it is a compound.
"c" is incorrect because such a thing (as far as we know) does not exist, unless we are talking about subatomic particles like protons, neutrons, and electrons that make up an atom.
"d" is incorrect because it describes a compound.
Analyze the graph to describe the solubility of barium nitrate, BaNO3.
At 60°C,________ (100g, 200g, 350g) must be added to 1 L of water to make a saturated solution.
At 25°C, the solubility is about ______ .(100 per L, 125 per L, 150 per L)
A solution that contains 600 g BaNO3 in
3 L of H2O at 70°C is ________. (saturated, supersaturated, unsaturated)
For a solution that contains 300 g BaNO3 in 3 L of H2O at 60°C to become saturated, _________ (100,200,300)g solute must be added.
Answer: The answers are
1) 200g
2) 100g per liter
3) unsaturated
4) 300
Explanation:
At 60°C, 200g must be added to 1 L of water to make a saturated solution. [Observing the graph we can see that at 60, 200g must be added]
At 25°C, the solubility is about 100 per L. [Observing the given graph]
A solution that contains 600g BaNO3 in 3L of H20 at 70°C is saturated.[By knowing the definition of Saturated solution]
For a solution that contains 300 g BaNO3 in 3L of H20 at 60°C to become saturated, 300g soluted must be added.
What are saturated solutions and solubility?A saturated solution is a solution that contains the maximum amount of solute that can be dissolved under the condition at which the solution exists.Solubility is the ability to be dissolved, especially in water or solution.Learn more about solutions, refer to:
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The shapes are placed in a basket
What is the probability of choosing a triangle?
A 12/12
B 2/12
C 3/12
D 4/12
Answer: Option B
Explanation: There are 12 total shapes and 2 triangles, therefore the probability would be 2/12
Answer:
B
Explanation:
How many protons and neutrons does the isotope Ab-298 have? 118 protons and 200 neutrons 200 protons and 178 neutrons 119 protons and 179 neutrons 119 protons and 180 neutrons
Answer:
119 protons and 179 neutrons
Explanation:
Given an element of the form AB-298, we know that 298 is the mass, which means it's the sum of the number of protons and number of neutrons.
Look at the answer choices and find the one whose numbers add up to 298. Only C (119 protons and 179 neutrons) is correct because 119 + 179 = 298.
Hope this helps!
1. Aerosol can carry warnings on their labels that say not to incinerate (burn) them or store
the cans above a certain temperature. The gas in a used aerosol can is at a pressure of
103 KPA at 25°C. If the can is thrown into a fire, what will the pressure be when the
temperature reaches 928°C?
3823.36 kPa will be the pressure be when the temperature reaches 928°C.
Explanation:
Data given of aerosol can:
Gas stored at a temperature T1 = 25 °C
pressure of the gas = 103 kPa OR 1.01 atm
If can thrown in fire then temperature T2 = 928 ° C
final pressure when can thrown in fire, P2 =?
Gay Lussac Law is applied to know the final volume:
[tex]\frac{P1}{T1}[/tex] = [tex]\frac{P2}{T2}[/tex]
rearranging the equation:
P2 = [tex]\frac{P1T2}{T1}[/tex]
putting the values in the equation:
P2 = [tex]\frac{1.01 X 928}{25}[/tex]
P2 = 37. 49 atm
The pressure will reach 37.49 atm or 3823.36 kPa is the pressure when it is thrown in the fire having temperature of 928 degree celsius.
Determine the volume, in liters, occupied by 0.015 molecules of oxygen at STp?
5.58 X [tex]10^{-25}[/tex] Litres is the volume, in liters, occupied by 0.015 molecules of oxygen at STP.
Explanation:
Data given:
molecules of oxygen = 0.015
number of moles of oxygen =?
temperature at STP = 273 K
Pressure at STP = 1 atm
volume = ?
R (gas constant) = 0.08201 L atm/mole K
to convert molecules to moles,
number of moles = [tex]\frac{molecules}{Avagadro's number}[/tex]
number of moles = 2.49 x [tex]10^{-26}[/tex]
Applying the ideal gas law since the oxygen is at STP,
PV = nRT
rearranging the equation:
V = [tex]\frac{nRT}{P}[/tex]
putting the values in the rearranged equation:
V = [tex]\frac{2.49 X10^{-26} X 0.08201 X 273}{1}[/tex]
V = 5.58 X [tex]10^{-25}[/tex] Litres.
When dissolved sodium hydroxide reacts with hydrogen sulfate, aqueous sodium, sulfate, water, and heat are formed. Write out the balanced equation for this
reaction and indicate what the coefficients are from left to right. (Note: Be sure to
keep the reactants and products in the same order that they appear in the
question.)
a) 2,1,1,2
b) 4,2,2,4
c) 1,1,1,1
d) 1,2,2,1
a) 2,1,1,2
When dissolved sodium hydroxide reacts with hydrogen sulfate, aqueous sodium, sulfate, water, and heat are formed.
This reaction is known as Neutralization reaction. Since a base and acid reacts together to produce a salt.
Lets, write balanced chemical equation:
2NaOH + H₂SO₄→ Na₂SO₄+ 2H₂O +HeatAs we see, the number of each atom on reactants is same as number of each atom on product. Thus this chemical equation is balanced.
Therefore, option a) is correct.
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The balanced chemical equation for the reaction of sodium hydroxide with hydrogen sulfate to form aqueous sodium sulfate, water, and heat is H₂SO₄ (aq) + 2NaOH(aq) → Na₂SO₄ (aq) + 2H₂O(l), with coefficients of 1, 2, 1, 2 from left to right, corresponding to answer (a).
Explanation:When dissolved sodium hydroxide reacts with hydrogen sulfate, the balanced chemical equation is:
H₂SO₄ (aq) + 2NaOH(aq) → Na₂SO₄ (aq) + 2H₂O(l)
The coefficients for this reaction from left to right are 1, 2, 1, and 2 respectively, which corresponds to answer (a) 2,1,1,2.
This reaction shows that sulfuric acid (H₂SO₄) is neutralized by sodium hydroxide (NaOH) to form sodium sulfate (Na₂SO₄) and water (H₂O). A mole ratio of 1:2 between sulfuric acid and sodium hydroxide is necessary to completely neutralize the acid, which shows the stoichiometric relationship between the reactants.
It takes 12.5mL of a 0.30M HCl solution to neutralize 285mL of NaOH solution.
What is the concentration of the NaOH solution?
Final answer:
To find the concentration of the NaOH solution, the moles of HCl used in the neutralization were calculated and, due to the 1:1 molar ratio of the reaction, were equivalent to the moles of NaOH. The number was then divided by the volume of the NaOH solution to find its concentration, which is 0.01316 M.
Explanation:
The question requires a calculation based on the concept of titration in chemistry, which is used to determine the concentration of an unknown solution. The balanced chemical equation for the neutralization reaction is HCl(aq) + NaOH(aq) → NaCl(aq) + H2O(l). Since it takes 12.5 mL of a 0.30 M HCl solution to neutralize 285 mL of NaOH solution, we start by calculating the number of moles of HCl used using the equation:
n = C × V, where n is the number of moles, C is the concentration in molarity, and V is the volume in liters.
nHCl = 0.30 moles/L × 0.0125 L = 0.00375 moles
Since the reaction between HCl and NaOH is a 1:1 molar ratio, the moles of NaOH will also be 0.00375. To find the concentration (molarity) of NaOH, we use:
M = n/V
MNaOH = 0.00375 moles / 0.285 L = 0.01316 M
Therefore, the concentration of the NaOH solution is 0.01316 M.
How many moles of H2SO4 are present in 0.500 L of a 0.150 M H2SO4 solution?
Answer: 0.075
Explanation:
(concentration in molarity)(volume in liter) = answer
0.15 mol/L *0.500L = 0.075 mol
The number of moles of H2SO4 in the given solution is 0.075 moles.
Explanation:The question is asking how many moles of H2SO4 are present in 0.500 L of a 0.150 M H2SO4 solution.
To answer this question, we can use the equation:
Moles of solute = concentration (M) x volume (L)
In this case, the concentration is 0.150 M and the volume is 0.500 L. Plugging these values into the equation, we get:
Moles of H2SO4 = 0.150 M x 0.500 L = 0.075 mol
Therefore, there are 0.075 moles of H2SO4 present in 0.500 L of the solution.
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What is the molarity of the solution if 1.50 grams of CaCl2 is dissolved to make 0.095 liters of solution?
Answer:
0.142 M
Explanation:
First, convert grams of CaCl2 to moles. The molar mass of CaCl2 is 110.984 g/mol. You should get 0.0135 moles.
Divide moles by liters to find molarity. You should get 0.142 M
What forces create the bent triatomic shape of a water molecule
Answer:
Repulsion Forces create the bent triatomic shape of a water molecule.
helppp!!!!!! pleaseeee
Answer:
A
Explanation:
you need to make a punnent squere
L L
l Ll Ll
l Ll Ll
Calculate the pH of a solution of 0.0025M H2SO4
Please help I dont get how to do these
Answer:
2.60
Explanation:
pH= - log [H₂SO₄]
H₂SO₄ is a strong acid only for the first H+ ion, so the concentration of H+ will equal the concentration of the whole molecule.
pH= - log [0.0025 M]
pH = 2.60
The pH of a solution of 0.0025M H₂SO₄ is 2.3 means the solution is highly acidic.
How do we calculate pH?pH of any solution will be calculated by using the below equation as:
pH = -log[H⁺]
Given that concentration of H₂SO₄ = 0.0025M
Let the volume of the acid is 1 liter means 0.0025 moles of H₂SO₄ are present.
1 moles of H₂SO₄ produces 2 moles of H⁺ ion So 0.0025 moles of H₂SO₄ produces 2(0.0025) = 0.0050 moles of H⁺ ion.In 1 liter of solution 0.005 M of H⁺ ions are present. On putting this value in pH equation, we get
pH = -log(0.005)
pH = -(-2.3) = 2.3
Hence required pH of solution is 2.3.
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Carbon Dioxide, CO2, is an Element?
A) True
B) False
C) Im not sure. I need more help with this topic
Answer:
false
Explanation:
element are one type of atom so CO2 is a compound because it is two type of elements with chemical bond.
how many sex chromosomes would be present in an individual with 80 chromosomes?
A)2
B)1
C)39
D)40
Answer:
D) 40
Explanation:
The number of sex chromosomes in an organism is half the number of chromosomes the individual has.
So if the individual has 80 chromosomes, they’ll have 80/2 =40 sex chromosomes.
Answer:
A)2
Explanation:
In Figure 9-2, are both kinds of atoms in balance, only nitrogen atoms in balance, only oxygen atoms
in balance, or neither kind of atom in balance?
Figure 9-2
A) The equation is balanced for both kinds of atoms
B) The equation is balanced for oxygen atoms only
C) The equation is balanced for nitrogen atoms only
D) The equation is balanced for either kind of atom
Answer:
C) The equation is balanced for nitrogen atoms only
Explanation:
nitrogen (black one) - 1 before and 1 after reaction
oxygen (white one) - 3 before and 2 after reaction
So,
C) The equation is balanced for nitrogen atoms only
How many moles of MgCl2 are contained in 261.5 mL of a 0.005 M MgCl2 solution? Please show your work.
The answer for the following problem is mentioned below.
Therefore the no of moles in the magnesium chloride solution is 1.3075 moles.Explanation:
Molarity:
The no of moles of moles present in one litre of the solution is called molarity
Given:
molarity of magnesium chloride (m) = 0.005 M
volume of magnesium chloride solution (V) = 261.5 ml
To find:
no of moles of magnesium chloride solution (n)
We know;
molarity = [tex]\frac{n}{V}[/tex]
m = [tex]\frac{n}{V}[/tex]
where;
m represents the molarity of the magnesium chloride solution
n represents the no of moles of magnesium chloride solution
V represents the volume of magnesium chloride solution
So;
0.005 = [tex]\frac{n}{261.5}[/tex]
n = 0.005 × 261.5
n = 1.3075 moles
Therefore the no of moles in the magnesium chloride solution is 1.3075 moles.
Was energy made or created
Answer:
Energy cannot be created nor destroyed
Explanation:
Law of conservation of energy