Hannah just finished building a house of cards that stands four stories high. She is worried that it will fall down. Which of the following statements must be true? A. A house of cards is too fragile and must fall down eventually due to gravity. B. If Hannah adds another card to the house of cards, then it will fall down. C. As long as nobody touches the house of cards, it will remain standing. D. If no unbalanced force acts upon the house of cards, then it will remain standing forever.
the answer is if no unbalanced force acts upon the house of cards then it will remain standing forever.
explanation:Newton's first law of motion states that an object at rest will remain at rest unless acted upon by an unbalanced force.
Even if nobody touches the house of cards, another type of unbalanced force (like wind) could knock the cards down, or if Hannah adds another card to the house of cards, it may or may not fall down.
However, if no unbalanced force acts upon the house of cards, then it will remain standing forever.
What location around the world are volcanoes consistently found? Along plate boundaries National parks Continent-ocean boundaries Along the equator
The answer is continent ocean boundaries.
Determine how many grams of co2 are produced by burning 4.37 g of c4h10.
To determine how many grams of CO2 are produced by burning 4.37 g of C4H10, we can use stoichiometry. The balanced equation shows that 1 mole of C4H10 produces 4 moles of CO2. By converting the mass of C4H10 to moles and then using the stoichiometric ratio, we can calculate the mass of CO2 produced.
Explanation:To determine how many grams of CO2 are produced by burning 4.37 g of C4H10, we can use stoichiometry. The balanced equation shows that 1 mole of C4H10 produces 4 moles of CO2. First, we need to convert the mass of C4H10 to moles by dividing it by the molar mass of C4H10. Then, we can use the stoichiometric ratio to calculate the number of moles of CO2 produced. Finally, we can convert the moles of CO2 to grams by multiplying it by the molar mass of CO2
Given:
Mass of C4H10 = 4.37 gMolar mass of C4H10 = 58.12 g/molMolar mass of CO2 = 44.01 g/molUsing the equation:
Mass of C4H10 (g) → Moles of C4H10 → Moles of CO2 → Mass of CO2 (g)
we can calculate:
4.37 g C4H10 * (1 mol C4H10 / 58.12 g C4H10) * (4 mol CO2 / 1 mol C4H10) * (44.01 g CO2 / 1 mol CO2) = 17.80 g CO2
Therefore, burning 4.37 g of C4H10 produces approximately 17.80 g of CO2.
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Describe a consequence of overpopulation of deer in the forest areas of the northeastern United States
Potassium-40 can decay into either calcium-40 or argon-40. All three of these atoms have essentially the same weight. Ninety percent of the potassium-40 will decay into calcium-40, and only ten percent will decay into argon-40. When argon-40 is produced by the radioactive decay of potassium-40 inside a rock, the argon-40 produced by the decay is a gas and is trapped inside the rock. The amount argon-40 trapped in a rock can be measured by grinding up the rock and capturing the liberated argon-40 gas.
Suppose the amount of potassium-40 inside a rock is measured to be 0.81 milligrams, and the amount of argon-40 gas trapped in the rock is measured to be 0.377 milligrams.
1. How much of the potassium-40 that was originally present inside the rock has undergone radioactive decay to produce argon-40?
The average atomic mass of oxygen is 15.9994 amu. The atomic masses of its three isotopes are as follows: O-16: 15.995 amu; O-17: 16.999 amu; O-18: 17.999 amu Which isotope is most likely to have the greatest abundance in nature? O–16 O–17 O–18 all three isotopes may be equally abundant
Answer: O-16
Explanation: To keep it short and sweet the answer is O-16
What is the oxidation state of each element in k2cr2o7?
The oxidation number is the charge when the bonds are ionic in the atom. The oxidation state of potassium is +1, oxygen is -2 and chromium is +6.
What is the oxidation state?The oxidation state or the number is the total of the electron gained or lost by the atom to form the chemical bond.
Potassium is always +1, and oxygen is -2 except in some cases.
The state can be shown as:
[tex]\rm K_{2} (+1 \times 2) = +2[/tex]
Cr (2x) = 2x
[tex]\rm O_{7} (-2 \times 7) = -14[/tex]
When the compound is neutral and the net charge is 0 then,
[tex]\begin{aligned} \rm +2 +2x + (-14) &= 0\\\\\rm 2x -12& = 0\\\\\rm x &= +6\end{aligned}[/tex]
Therefore, the oxidation number of chromium is +6.
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The atomic number of gold (Au) is 79, and it has a mass number of 197. How many electrons are present in each atom of gold?
The molar volume of a gas at STP, in liters, is ___ .
You can use the molar volume to convert 2 mol of any gas to ___ L.
You can also use the molar volume to convert 11.2 L of any gas to ____ mol. Avogadro’s law tells you that 1.2 L of O2(g) and 1.2 L of NO2(g) are ______-numbers of moles of gas.
Let us consider the following points
a) The volume of one mole of an ideal gas at STP (273.15 K and 1 atm) is 22.4 L.
b) the number of moles of in any given volume of gas can be calculated as:
[tex]Moles=\frac{22.4L}{Volumegiven}[/tex]
Solutions:
1) The molar volume of a gas at STP, in liters, is 22.4 L.
2) You can use the molar volume to convert 2 mol of any gas to 44.8 L
Volume = moles X 22.4L
Volume = 2 X 22.4 = 44.8L
3) You can also use the molar volume to convert 11.2 L of any gas to 0.5 mol.
As mentioned above
[tex]mole=\frac{volume}{22.4}=\frac{11.2}{22.4}=0.5mol[/tex]
4) Avogadro’s law tells you that 1.2 L of O2(g) and 1.2 L of NO2(g) are ______-numbers of moles of gas.
The moles of oxygen will be:
[tex]mole=\frac{volume}{22.4}=\frac{1.2}{22.4}=0.0536mol[/tex]
The moles of nitrogen dioxide will be:
[tex]mole=\frac{volume}{22.4}=\frac{1.2}{22.4}=0.0536mol[/tex]
Total moles = 0.0536+0.0536 = 0.1072 moles
The molar volume of a gas at STP is 22.4 L. Therefore, 2 moles of any gas equals 44.8 L and 11.2 L of any gas equals 0.5 moles. Avogadro's law states that 1.2 L of O2(g) and 1.2 L of NO2(g) have the same number of moles.
Explanation:The molar volume of a gas at Standard Temperature and Pressure (STP) is approximately 22.4 liters. Therefore, if you have 2 moles of any gas at STP, this would occupy a volume of 2 x 22.4 = 44.8 liters. Conversely, if you have 11.2 liters of any gas at STP, this equates to 11.2 / 22.4 = 0.5 moles of gas. According to Avogadro's law, equal volumes of gases, at the same temperature and pressure, contain equal numbers of molecules. So, 1.2 liters of O2(g) and 1.2 liters of NO2(g) contain the same number of moles of gas.
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A certain material has a mass of 12.48 g while occupying 12.48 cm3 of space. What is this material?
Answer: The material is water as it has density of [tex]1g/cm^3[/tex]
Explanation:
Density is defined as the mass contained per unit volume. It is characteristic of a material.
[tex]Density=\frac{mass}{Volume}[/tex]
Given : Mass of object =12.48 grams
Volume of the object = [tex]12.48cm^3[/tex]
Putting in the values we get:
[tex]Density=\frac{12.48g}{12.48cm^3}[/tex]
[tex]Density=1g/cm^3[/tex]
Thus the density of the material is [tex]1g/cm^3[/tex] and material is water which has density of [tex]1g/cm^3[/tex].
What is the overall nuclear fusion reaction in the sun?
A 595 mL sample of chlorine gas at 24.7°C is held at constant pressure while it is heated and the volume of the gas expands to 876mL. What is the new temperature in Kelvin?
A) 83.7 K
B) 202 K
C) 365 K
D) 438 K
A certain reaction has an activation energy of 69.0 kj/mol and a frequency factor of a1 = 3.40×1012 m−1s−1 . what is the rate constant, k, of this reaction at 22.0 ∘c ? express your answer with the appropriate units. indicate the multiplication of units explicitly either with a multiplication dot (asterisk) or a dash.
when butane reacts with oxygen, the temperature of the surrounding area
Answer:
increases.
Explanation:
If 17.4 mL of 0.800 M HCl solution are needed to neutralize 5.00 mL of a household ammonia solution, what is the molar concentration of the ammonia?
Answer: The concentration of ammonia is 2.784 M
Explanation:
To calculate the concentration of acid, we use the equation given by neutralization reaction:
[tex]n_1M_1V_1=n_2M_2V_2[/tex]
where,
[tex]n_1,M_1\text{ and }V_1[/tex] are the n-factor, molarity and volume of acid which is [tex]HCl[/tex]
[tex]n_2,M_2\text{ and }V_2[/tex] are the n-factor, molarity and volume of base which is ammonia
We are given:
[tex]n_1=1\\M_1=0.800M\\V_1=17.4mL\\n_2=1\\M_2=?M\\V_2=5.00mL[/tex]
Putting values in above equation, we get:
[tex]1\times 0.800\times 17.4=1\times M_2\times 5.00\\\\M_2=2.784M[/tex]
Hence, the concentration of ammonia is 2.784 M
The molar concentration of the household ammonia solution is 2.78 M.
Let's start by writing the neutralization reaction:
HCl (aq) + NH₃ (aq) → NH₄Cl (aq)
The number of moles of HCl required to neutralize the ammonia solution can be calculated from the volume and molarity of the HCl solution:
moles HCl = Molarity x Volume (in liters) = 0.800 M x 17.4 mL x (1 L / 1000 mL) = 0.01392 mol
Since the reaction is 1:1, the number of moles of NH₃ required to neutralize the HCl is also 0.01392 mol.
The molar concentration of the ammonia solution can be calculated from the number of moles and the volume of the solution:
Molarity = moles / volume (in liters) = 0.01392 mol / 5.00 mL x (1 L / 1000 mL) = 2.78 M
Therefore, the molar concentration of the household ammonia solution is 2.78 M.
Predict whether the compounds are soluble or insoluble in water.
Soluble
Insoluble
Generally, polar and ionic compounds are soluble in water, while non-polar compounds are insoluble. However, conclusively predicting a compound's solubility requires additional information about the compound.
Explanation:The solubility of compounds in water depends on the chemical nature of the compound. Generally, polar and ionic compounds are soluble in water due to its polar nature. This is because 'like dissolves like'. So, compounds such as sodium chloride, sugar, etc., are soluble in water.
On the other hand, non-polar compounds are usually insoluble in water. This includes many organic compounds like oils and fats.
However, the solubility of a compound can't be predicted with absolute certainty without additional information about the compounds' molecular structure, polarity, or the presence of functional groups.
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For a certain gas-phase reaction, the fraction of products in an equilibrium mixture is increased by either increasing the temperature or increasing the volume of the reaction vessel. complete the sentences to determine if the reaction is endothermic or exothermic and to determine which side of the equation has more molecules.
Final answer:
The reaction is endothermic because increasing the temperature increases the fraction of products, as energy acts as a reactant. Moreover, since the product fraction increases with volume, the products' side has more molecules, showing that the reaction has a larger number of gaseous products.
Explanation:
For a gas-phase reaction, the fraction of products in an equilibrium mixture is increased by either increasing the temperature or increasing the volume of the reaction vessel. To determine if the reaction is endothermic or exothermic, we can use the behavior of the system in response to these changes. When temperature is increased for an endothermic reaction, energy can be considered as a reactant, therefore, the equilibrium shifts towards the products. Conversely, for an exothermic reaction, which releases energy, an increase in temperature would shift the equilibrium towards reactants. Since increasing the temperature increases the fraction of products, the reaction is endothermic.
Regarding the change in volume, an increase in volume results in a decrease in pressure and favors the side of the reaction with more gas molecules. If the fraction of products increases with increased volume, this indicates that the side with the products has more gas molecules. Therefore, the reaction equation has more molecules on the products' side.
What is the concentration of a phosphoric acid solution of a 25.00 mL sample if the acid requires 42.24 mL of 0.135 M NaOH for neutralization?
Please explain your steps.
Answer: The volume of 0.10 M NaOH required to neutralize 30 ml of 0.10 M HCl is, 30 ml.
Explanation:
According to the neutralization law,
[tex]n_1M_1V_1=n_2M_2V_2[/tex]
where,
[tex]M_1[/tex] = molarity of NaOH solution = 0.135 M
[tex]V_1[/tex] = volume of NaOH solution = 42.24 ml
[tex]M_2[/tex] = molarity of [tex]H_3PO_4[/tex] solution = ?M
[tex]V_2[/tex] = volume of [tex]H_3PO_4[/tex] solution = 25 ml
[tex]n_1[/tex] = valency of [tex]NaOH[/tex] = 1
[tex]n_2[/tex] = valency of [tex]H_3PO_4[/tex] = 3
[tex]1\times (0.135M)\times 42.24=3\times M_2\times 25[/tex]
[tex]M_2=0.076M[/tex]
Therefore, the concentration of 0.076 M of phosphoric acid of a 25 ml is required to neutralize 42.24 ml of 0.135 M NaOH.
when sodium hydroxide is dissolved in water, energy is released as heat to the surroundings l, causing an increase in the solutions temperature. which of the following best describes this type of reaction?
a.- exothermic
b.- exothermic
c.- decomposition
d.- synthesis
Final answer:
The process of sodium hydroxide dissolving in water and releasing heat is best described as an exothermic reaction, as it involves the release of energy to the surroundings.
Explanation:
When sodium hydroxide (NaOH) is dissolved in water, it disassociates into sodium (Na+) and hydroxide (OH-) ions, releasing energy in the form of heat to the surroundings, and causing an increase in the temperature of the solution. This type of reaction, where energy is released, is best described as an exothermic reaction. These reactions are characterized by the release of heat and a rise in the temperature of the surroundings. Care must be taken when dissolving sodium hydroxide in water due to the significant amount of heat produced.
It is important to note that this is different from an endothermic reaction, where energy is absorbed from the surroundings, causing a decrease in temperature. The process of sodium hydroxide dissolving in water is not a decomposition reaction, as that involves a single compound breaking down into two or more simpler substances. It also does not fit the definition of a synthesis reaction, which involves combining simpler substances to form a more complex product.
Final answer:
The dissolution of sodium hydroxide in water, which releases heat and increases the solution's temperature, is an exothermic reaction.
Explanation:
When sodium hydroxide is dissolved in water and energy is released as heat, increasing the solution's temperature, this type of reaction is best described as exothermic. An exothermic reaction is characterized by the release of energy to the surroundings, often in the form of heat. As the sodium hydroxide (NaOH) dissolves, it disassociates into sodium (Na+) and hydroxide (OH-) ions, and the process releases a significant amount of heat, indicating that the solution becomes very basic and the temperature rises.
the closer an object is to the center of earth the ------------------ the gravitational force on that object
A greater
B less
these science
Answer:
Greater
Explanation:
According to the law of universal gravitation, the force of gravitation is directly proportional to the product of the masses of the two objects and INDIRECTLY proportional to the square of the distance. In short, the bigger the masses, the stronger the gravitational force, the lesser the distance between the two objects, the greater the gravitational force.
Write formulas for these hydrates sodium sulfate decahydrate
Final answer:
The chemical formulas for the hydrates are Na₂SO₄⋅10H₂O (sodium sulfate decahydrate), CaCl₂⋅2H₂O (calcium chloride dihydrate), and Ba(OH)₂⋅8H₂O (barium hydroxide octahydrate).
Explanation:
To write the chemical formulas of hydrates, you start by writing the formula for the anhydrous compound (the compound without water) followed by a dot, then the number of water molecules, represented as H₂O. Each number of water molecules is prefaced by a prefix that indicates how many molecules of water are included.
Sodium sulfate decahydrate, which has 10 water molecules, is written as Na₂SO₄⋅10H₂O.Calcium chloride dihydrate, which has 2 water molecules, is written as CaCl₂⋅2H₂O.Barium hydroxide octahydrate, which has 8 water molecules, is written as Ba(OH)₂⋅8H₂O.These formulas indicate the precise number of water molecules associated with each ionic compound.
How many grams of sodium iodide Nai must be used to produce 51.9 G of iodine I2
Final answer:
To produce 51.9 grams of iodine (I2), approximately 61.2 grams of sodium iodide (NaI) must be used. This calculation is based on stoichiometry and the molar masses of NaI and I₂.
Explanation:
To calculate the amount of sodium iodide (NaI) needed to produce a given amount of iodine (I₂), we will use stoichiometry based on the balanced chemical equation of the reaction. The molecular weight of I₂ (iodine) is approximately 253.8 g/mol (126.9 g/mol for each iodine atom). Let's calculate how many moles of I₂ are in 51.9 grams.
Step 1. Convert from grams to moles of I₂ using the molar mass of I₂ in the unit conversion factor.
51.9 g I₂ × (1 mol I₂ / 253.8 g I₂) = 0.204 moles of I₂.The balanced chemical equation for the production of iodine from sodium iodide may look like this, depending on the reacting substances involved:
2 NaI + Cl₂ → 2 NaCl + I₂From the balanced equation, we see that the molar ratio between NaI and I₂ is 2:1. This means it takes 2 moles of NaI to produce 1 mole of I₂.
Step 2. Use the stoichiometry to find the moles of NaI needed.
0.204 moles I₂ × (2 moles NaI / 1 mole I₂) = 0.408 moles of NaI needed.Step 3. Convert moles of NaI to grams.
The molar mass of NaI (22.99 g/mol for Na + 126.9 g/mol for I) is approximately 149.89 g/mol.0.408 moles NaI × (149.89 g NaI / 1 mole NaI) = 61.2 grams of NaI.Therefore, to produce 51.9 grams of iodine (I₂), approximately 61.2 grams of sodium iodide (NaI) must be used.
A 0.210 mol sample of pcl5(g) is injected into an empty 2.45 l reaction vessel held at 250 °c. calculate the concentrations of pcl5(g) and pcl3(g) at equilibrium.
C2H4(g) + H2(g) mc009-1.jpg C2H6(g) + 137 kJ What happens to the amount of ethane (C2H6) when the temperature of the system is increased? The amount of ethane decreases. The amount of ethane increases initially and then decreases. The amount of ethane increases. The amount of ethane decreases initially and then increases.
Answer:
A) The amount of ethane decreases.
Explanation:
Treatment of an alpha,beta-unsaturated ketone with basic aqueous hydrogen peroxide yields an epoxy ketone. the reaction is specific to unsaturated ketones; isolated alkene double bonds do not react. on a sheet of paper, write a mechanism for the alkene to epoxide reaction. then, in the window below, draw the first intermediate in your mechanism.
What happens when naoh is added to a buffer composed of ch3cooh and ch3coo−?
pH of buffer solution containing [tex]{\mathbf{C}}{{\mathbf{H}}_{\mathbf{3}}}{\mathbf{COOH}}[/tex] and [tex]{\mathbf{C}}{{\mathbf{H}}_{\mathbf{3}}}{\mathbf{COOH}}[/tex] does not change on addition of NaOH to the buffer.
Further explanation:
Buffer solution:
The aqueous solution that consists of weak acid and its conjugate base is known as buffer solution. Such solutions resist any change in their pH on addition of strong base or acid.
pH is used to determine acidity or basicity of solutions. Solutions with pH less than 7 are acidic in nature, those with pH 7 are neutral and those with pH more than 7 are basic.
Classification of buffers:
Acidic buffer:
Solutions of weak acid and its conjugate base with pH less than 7 are acidic. Mixture of acetic acid and sodium acetate is an example of acidic buffer.
Basic buffer:
Solutions of weak base and its conjugate acid with pH more than 7 are basic in nature. Mixture of ammonium chloride and ammonium hydroxide is an example of basic or alkaline buffer.
[tex]{\text{C}}{{\text{H}}_{\text{3}}}{\text{COOH}}[/tex] is a weak acid while NaOH is a strong base so these react with each other to form respective salt and water. Reaction between these two occurs as follows:
[tex]{\text{C}}{{\text{H}}_{\text{3}}}{\text{COOH}} + {\text{NaOH}} \to {\text{C}}{{\text{H}}_{\text{3}}}{\text{COONa}} + {{\text{H}}_{\text{2}}}{\text{O}}[/tex]
The salt formed by reaction of [tex]{\text{C}}{{\text{H}}_{\text{3}}}{\text{COOH}}[/tex] with NaOHis then dissociated to form its ions as follows:
[tex]{\text{C}}{{\text{H}}_{\text{3}}}{\text{COONa}} \rightleftharpoons {\text{C}}{{\text{H}}_{\text{3}}}{\text{CO}}{{\text{O}}^ - } + {\text{N}}{{\text{a}}^ + }[/tex]
Ionic identity [tex]{\text{C}}{{\text{H}}_{\text{3}}}{\text{CO}}{{\text{O}}^ - }[/tex] reacts with water to form uncharged [tex]{\text{C}}{{\text{H}}_{\text{3}}}{\text{COOH}}[/tex] again. Reaction for this is as follows:
[tex]{\text{CHCO}}{{\text{O}}^ - } + {{\text{H}}_{\text{2}}}{\text{O}} \rightleftharpoons {\text{C}}{{\text{H}}_{\text{3}}}{\text{COOH}} + {\text{O}}{{\text{H}}^ - }[/tex]
By going through above series of reactions, effect of addition of NaOH is neutralized by buffer containing [tex]{\text{C}}{{\text{H}}_{\text{3}}}{\text{COOH}}[/tex] and [tex]{\text{C}}{{\text{H}}_{\text{3}}}{\text{CO}}{{\text{O}}^ - }[/tex]. Hence pH of buffer solution does not undergo any change in it.
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The mass of ethylene glycol: https://brainly.com/question/4053884 Basis of investigation for the scientists: https://brainly.com/question/158048Answer details:
Grade: Senior School
Subject: Chemistry
Chapter: Buffer solutions
Keywords: buffer solution, pH, CH3COOH, NaOH, CH3COO-, weak acid, strong base, acidic buffer, basic buffer, less than 7, more than 7, H2O, OH-, CH3COONa, reaction, conjugate base.
How many grams of caf2 would be needed to produce 8.41×10-1 moles of f2?
Final answer:
To produce 8.41×10⁻¹ moles of F2, 65.7 grams of CaF₂ are needed, calculated using stoichiometry and the molar mass of CaF₂ (78.08 g/mol).
Explanation:
The question asks how many grams of CaF₂ are needed to produce 8.41×10⁻¹ moles of F₂. Based on stoichiometry, the reaction involves CaF₂ decomposing to produce Ca and F₂. Since each formula unit of CaF₂ contains two fluorine atoms, it will produce 1 mole of F₂ for every mole of CaF₂ decomposed. Therefore, to produce 8.41×10⁻¹ moles of F₂, we also need 8.41×10⁻¹ moles of CaF₂. Using the formula mass of CaF₂ (78.08 g/mol), we can calculate the mass of CaF₂ needed.
Mass of CaF₂ = moles of CaF₂ × molar mass of CaF₂
= 8.41×10⁻¹ moles × 78.08 g/mol
= 65.7 g of CaF2
How many moles of CaCl2 have you delivered to the flask if you add 20.53mL of 0.511 M CaCl2 from the buret
We have that for the Question "How many moles of CaCl2 have you delivered to the flask if you add 20.53mL of 0.511 M CaCl2 from the buret" it can be said that no of moles of solute is
[tex]no of moles of solute=0.011[/tex]
From the question we are told
How many moles of CaCl2 have you delivered to the flask if you add 20.53mL of 0.511 M CaCl2 from the buret
Generally the equation for the morality is mathematically given as
[tex]M=\frac{no of moles of solute}{volume of solution litre}[/tex]
Therefore
[tex]The volume of CaCl_2 =\frac{20.53}{1000}[/tex]
Hence
no of moles of solute=molality*volume*solution
[tex]no\ of\ moles\ of\ solute=0.511*\frac{20.53}{1000}[/tex]
[tex]no of moles of solute=0.011[/tex]
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An aqueous solution has an h3o+ concentration of 4.4×10-2 m. calculate [oh–] for this solution.
Calculate the density of SO3 gas at STP. Show all work.