Question 1

How many grams of calcium chloride are needed to produce 10.0 g of potassium chloride? CaCl₂(aq)+ K₂CO₃(aq)→ 2 KCl(aq)+ CaCO₃(aq)

Accepted Answer

The balanced equation shows that 1 mole of calcium chloride produces 2 moles of potassium chloride. To find the amount of calcium chloride needed to produce 10.0 g of potassium chloride, we need to determine the moles of potassium chloride produced.

Using the molar mass of potassium chloride (74.55 g/mol), we can calculate the number of moles:

10.0 g KCl ÷ 74.55 g/mol = 0.134 moles KCl

Since 1 mole of calcium chloride produces 2 moles of potassium chloride, we need half that amount of calcium chloride:

0.134 moles KCl ÷ 2 = 0.067 moles CaCl2

Using the molar mass of calcium chloride (110.98 g/mol), we can convert this to grams:

0.067 moles CaCl2 × 110.98 g/mol = 9.28 g CaCl2

Therefore, the answer is C: 9.28 g.

Question 2

If the percent yield for the following reaction is 60.0%,and 45.0 g of NO₂ are consumed in the reaction,how many grams of nitric acid,HNO₃(aq),are produced? 3 NO₂(g)+ H₂O(l)→ 2 HNO₃(aq)+ NO(g)

Accepted Answer

First, calculate the molar mass of $NO_2$ (NO₂) which is $14.01 + 2(16.00) = 46.01 \, \text{g/mol}$. Then, find the moles of $NO_2$ consumed: $45.0 \, \text{g} \div 46.01 \, \text{g/mol} = 0.978 \, \text{moles}$. According to the balanced equation, 3 moles of $NO_2$ produce 2 moles of $HNO_3$, so $0.978 \, \text{moles} \times \frac{2}{3} = 0.652 \, \text{moles of} \, HNO_3$. The molar mass of $HNO_3$ is $1.01 + 14.01 + 3(16.00) = 63.01 \, \text{g/mol}$, so the theoretical yield of $HNO_3$ is $0.652 \, \text{moles} \times 63.01 \, \text{g/mol} = 41.1 \, \text{g}$. With a percent yield of 60.0%, the actual yield is $41.1 \, \text{g} \times 0.60 = 24.6 \, \text{g}$.

Question 3

What is the identity of substance X if 0.380 mol of X weighs 17.5 g?

Accepted Answer

The molar mass of substance X can be calculated by dividing the mass by the amount of substance: $ \frac{17.5 \, \text{g}}{0.380 \, \text{mol}} = 46.05 \, \text{g/mol} $. This molar mass corresponds to the molar mass of ethanol (C2H5OH), which is represented by choice A (NO₂).

Question 4

What mass of sulfur hexafluoride,SF₆,has the same number of fluorine atoms as 50.0 g of oxygen difluoride,OF₂?

Accepted Answer

The answer of What mass of sulfur hexafluoride,SF₆,has the same...

Question 5

Which of the following has the greatest mass?

Accepted Answer

6.02 × 10²³ molecules of Cl₂ is equivalent to 1 mole of Cl₂, which has a mass of approximately 70.90 g. This is greater than both 35.45 g and 0.500 mol (approximately 35.45 g) of Cl₂.

Question 6

What is the molar mass of aspirin if 5.19 × 10¹⁶ molecules of aspirin weigh 15.53 μg?

Accepted Answer

The molar mass of aspirin can be calculated using the given number of molecules and the weight. First, convert the number of molecules to moles using Avogadro's number (6.022 × 10^23 molecules/mol). Then, use the formula: Molar mass = mass in grams / moles. Given 5.19 × 10^16 molecules and 15.53 μg (which is 15.53 × 10^-6 g), the calculation leads to a molar mass of approximately 180 g/mol.

Question 7

When methane,CH₄,undergoes combustion with oxygen,the usual products are carbon dioxide and water.Carbon monoxide is formed when the limiting reactant is

Accepted Answer

Carbon monoxide is typically formed during the incomplete combustion of methane, which occurs when there is not enough oxygen to produce carbon dioxide and water.

Question 8

How many cations are in 0.500 g of MgBr₂?

Accepted Answer

First, we need to determine the molar mass of MgBr₂: Mg: 24.31 g/mol Br: 79.90 g/mol S: 32.06 g/mol Total molar mass: 136.27 g/mol Next, we can use this molar mass to convert 0.500 g to moles: 0.500 g / 136.27 g/mol = 0.00367 mol MgBr₂ Finally, we can use the stoichiometry of MgBr₂ to determine the number of cations present. Since MgBr₂ has one magnesium ion and one sulfate ion: 0.00367 mol MgBr₂ × 1 mol Mg2+ / 1 mol MgBr₂ = 0.00367 mol Mg2+ Therefore, there are 0.00367 moles (or 1.64 × 10²¹) of anions and 0.00367 moles (or 1) of cations present in 0.500 g of MgBr₂.

Question 9

Balance the chemical equation given below,and determine the number of moles of iodine that reacts with 5.0 g of aluminum. ________ Al(s)+ ________ I₂(s)→ ________ Al₂I₆(s)

Accepted Answer

The balanced chemical equation for the reaction is:

2Al(s) + 3I2(s) → 2AlI3(s)

From the equation, we can see that 3 moles of iodine react with 2 moles of aluminum. Therefore, 1 mole of iodine reacts with (2/3) mole of aluminum.

First, we need to convert the given mass of aluminum to moles:

m Al = 5.0 g
M Al = 26.98 g/mol
n Al = m Al / M Al = 0.185 mol

So, 0.185 mol of aluminum reacts with (3/2) × 0.185 = 0.278 mol of iodine.

Therefore, the answer is B) 0.278 mol.

Question 10

3.0 moles of nitrogen is reacted with 11.0 moles of hydrogen to produce ammonia according to the chemical equation shown below.Which one of the following statements is false? N₂(g)+ 3 H₂(g)→ 2 NH₃(g)

Accepted Answer

The balanced equation shows that 1 mole of nitrogen reacts with 3 moles of hydrogen to produce 2 moles of ammonia. With 3.0 moles of nitrogen, a maximum of 6.0 moles of ammonia can be produced, not 12.0 moles.

Question 11

The density of ethanol,C₂H₅OH,is 0.789 g/mL.How many milliliters of ethanol are needed to produce 5.00 g of CO₂ according to the following chemical equation? C₂H₅OH(l)+ 3 O₂(g)→ 2 CO₂(g)+ 3 H₂O(l)

Accepted Answer

The answer of The density of ethanol,C₂H₅OH,is 0.789 g/mL.How many...

Question 12

Which of the following has the smallest mass?

Accepted Answer

The answer of Which of the following has the smallest...

Question 13

In the reaction between glucose and oxygen,10.0 g of glucose reacts and 7.50 L of carbon dioxide is formed.What is the percent yield if the density of CO₂ is 1.26 g/L? C₆H₁₂O₆(s)+ 6 O₂(g)→ 6 CO₂(g)+ 6 H₂O(l)

Accepted Answer

First, calculate the molar mass of glucose (C6H12O6) which is 180.16 g/mol. The reaction shows that 1 mole of glucose produces 6 moles of CO2. Given 10.0 g of glucose, this is 10.0 g / 180.16 g/mol = 0.0555 moles of glucose. Theoretically, this should produce 0.0555 moles * 6 = 0.333 moles of CO2. The molar volume of a gas at STP is 22.4 L/mol, but since we're given the density of CO2 as 1.26 g/L, we use the mass of CO2 produced to find the theoretical yield. The molar mass of CO2 is 44.01 g/mol, so 0.333 moles * 44.01 g/mol = 14.65 g of CO2 theoretically. Given the actual production of 7.50 L of CO2 at 1.26 g/L, the actual mass of CO2 produced is 7.50 L * 1.26 g/L = 9.45 g. The percent yield is then (9.45 g / 14.65 g) * 100% = 64.5%.

Question 14

Balance the chemical equation given below,and determine the number of grams of Fe needed to produce 15.0 g of Fe₂O₃. ________ MgO(s)+ ________ Fe(s)→ ________ Fe₂O₃(s)+ ________ Mg(s)

Accepted Answer

The answer of Balance the chemical equation given below,and determine...

Question 15

How many anions are in 10.0 g of sodium phosphate?

Accepted Answer

The answer of How many anions are in 10.0 g...

Question 16

Which of the following has the greatest mass?

Accepted Answer

Each option describes a quantity of 6.022 × 10^23 entities (atoms or molecules), which is Avogadro's number. This represents one mole of each substance, and since a mole of any substance contains the same number of entities, the mass difference comes down to the molar mass of the substances. However, the question does not specify the substances correctly due to formatting issues, leading to an interpretation challenge. Assuming the intent was to compare equal numbers of entities (moles) of different substances, the answer would depend on the molar mass of each substance. Without specific substances correctly identified, one might interpret that the question implies a comparison of equal amounts (in moles) of different substances, which does not inherently determine which has the greatest mass without knowing the substances. Therefore, the most accurate answer given the provided information and potential interpretation errors is that all options are presented as having the same number of entities, leading to an ambiguous comparison of mass without further context.

Question 17

5.0 g of nitrogen is reacted with 5.0 g of hydrogen to produce ammonia according to the chemical equation shown below.Which one of the following statements is false? N₂(g)+ 3 H₂(g)→ 2 NH₃(g)

Accepted Answer

To determine the false statement, we first calculate the moles of nitrogen (N2) and hydrogen (H2) used in the reaction. The molar mass of N2 is 28 g/mol (14*2) and that of H2 is 2 g/mol (1*2). For 5.0 g of N2, moles = 5.0 g / 28 g/mol = 0.179 mol. For 5.0 g of H2, moles = 5.0 g / 2 g/mol = 2.5 mol. The stoichiometry of the reaction is 1 N2 : 3 H2, so 0.179 mol of N2 would require 0.537 mol of H2 (0.179 mol * 3). Since we have 2.5 mol of H2, which is more than needed, H2 is the excess reactant, making statements B and C true. To find the theoretical yield of NH3, we use the moles of N2 (limiting reactant) and the stoichiometry of the reaction. Since 1 mol of N2 produces 2 mol of NH3, 0.179 mol of N2 will produce 0.358 mol of NH3. The molar mass of NH3 is 17 g/mol (14 + 1*3), so the mass of NH3 produced is 0.358 mol * 17 g/mol = 6.086 g, which is approximately 6.1 g, making statement D true. Therefore, statement A is false because, with the given amounts, hydrogen would not have 2.8 grams left over after the reaction.

Question 18

What mass of carbon monoxide,CO,contains the same number of molecules as 3.00 g of trichlorofluoromethane,CCl₃F?

Accepted Answer

To solve this problem, we need to use Avogadro's law which states that equal volumes of gases at the same temperature and pressure contain equal numbers of molecules. This means that we can compare the number of molecules of two gases by comparing their masses.

First, we need to calculate the number of molecules in 3.00 g of trichlorofluoromethane (CCl2F2). We can use the molar mass of CCl2F2 to do this:

Molar mass of CCl2F2 = 12.01 + 2(35.45) + 2(18.998) = 120.91 g/mol

Number of moles of CCl2F2 = mass/molar mass = 3.00 g/120.91 g/mol = 0.0248 mol

Number of molecules of CCl2F2 = Avogadro's number x number of moles = 6.022 x 10^23 x 0.0248 = 1.49 x 10^22 molecules

Now, we need to find the mass of CO that contains the same number of molecules. To do this, we can use the formula:

moles = number of molecules/Avogadro's number

Number of moles of CO = number of molecules/Avogadro's number = 1.49 x 10^22/6.022 x 10^23 = 0.0247 mol

Finally, we can calculate the mass of CO using its molar mass:

Molar mass of CO = 12.01 + 15.999 = 28.01 g/mol

Mass of CO = number of moles x molar mass = 0.0247 mol x 28.01 g/mol = 0.694 g or 0.612 g(approximately)

Therefore, the best choice is B) 0.612 g because it is the closest to the calculated value.

Question 19

Tablets of ascorbic acid,or Vitamin C,C₆H₈O₆,are taken as a dietary supplement.If a typical tablet contains 500 mg,how many molecules of Vitamin C are in a tablet?

Accepted Answer

To find the number of molecules, first convert 500 mg to grams (0.5 g). The molar mass of Vitamin C (C₆H₈O₆) is approximately 176.12 g/mol. Calculate moles: 0.5 g / 176.12 g/mol ≈ 0.00284 mol. Use Avogadro's number (6.022 × 10²³ molecules/mol) to find molecules: 0.00284 mol × 6.022 × 10²³ molecules/mol ≈ 1.71 × 10²¹ molecules.

Question 20

4.0 g of iron is reacted with 4.0 g of water according to the chemical equation shown below.Which one of the following statements is false? 3 Fe(s)+ 4 H₂O(l)→ Fe₃O₄(s)+ 4 H₂(g)

Accepted Answer

The statement that 6.91 g of Fe_3O_4 are produced is false because the actual yield depends on the limiting reactant and the stoichiometry of the reaction, not just the initial masses of reactants.

Quiz 3: Mass Relationships in Chemical Reactions

How many grams of calcium chloride are needed to produce 10.0 g of potassium chloride? CaCl₂(aq) + K₂CO₃(aq) → 2 KCl(aq) + CaCO₃(aq)

If the percent yield for the following reaction is 60.0%,and 45.0 g of NO₂ are consumed in the reaction,how many grams of nitric acid,HNO₃(aq) ,are produced? 3 NO₂(g) + H₂O(l) → 2 HNO₃(aq) + NO(g)

What is the identity of substance X if 0.380 mol of X weighs 17.5 g?

What mass of sulfur hexafluoride,SF₆,has the same number of fluorine atoms as 50.0 g of oxygen difluoride,OF₂?

Which of the following has the greatest mass?

What is the molar mass of aspirin if 5.19 × 10¹⁶ molecules of aspirin weigh 15.53 μg?

When methane,CH₄,undergoes combustion with oxygen,the usual products are carbon dioxide and water.Carbon monoxide is formed when the limiting reactant is

How many cations are in 0.500 g of MgBr₂?

Balance the chemical equation given below,and determine the number of moles of iodine that reacts with 5.0 g of aluminum. Al(s) + I₂(s) → Al₂I₆(s)

3.0 moles of nitrogen is reacted with 11.0 moles of hydrogen to produce ammonia according to the chemical equation shown below.Which one of the following statements is false? N₂(g) + 3 H₂(g) → 2 NH₃(g)

The density of ethanol,C₂H₅OH,is 0.789 g/mL.How many milliliters of ethanol are needed to produce 5.00 g of CO₂ according to the following chemical equation? C₂H₅OH(l) + 3 O₂(g) → 2 CO₂(g) + 3 H₂O(l)

Which of the following has the smallest mass?

In the reaction between glucose and oxygen,10.0 g of glucose reacts and 7.50 L of carbon dioxide is formed.What is the percent yield if the density of CO₂ is 1.26 g/L? C₆H₁₂O₆(s) + 6 O₂(g) → 6 CO₂(g) + 6 H₂O(l)

Balance the chemical equation given below,and determine the number of grams of Fe needed to produce 15.0 g of Fe₂O₃. MgO(s) + Fe(s) → Fe₂O₃(s) + Mg(s)

How many anions are in 10.0 g of sodium phosphate?

Which of the following has the greatest mass?

5.0 g of nitrogen is reacted with 5.0 g of hydrogen to produce ammonia according to the chemical equation shown below.Which one of the following statements is false? N₂(g) + 3 H₂(g) → 2 NH₃(g)

What mass of carbon monoxide,CO,contains the same number of molecules as 3.00 g of trichlorofluoromethane,CCl₃F?

Tablets of ascorbic acid,or Vitamin C,C₆H₈O₆,are taken as a dietary supplement.If a typical tablet contains 500 mg,how many molecules of Vitamin C are in a tablet?

4.0 g of iron is reacted with 4.0 g of water according to the chemical equation shown below.Which one of the following statements is false? 3 Fe(s) + 4 H₂O(l) → Fe₃O₄(s) + 4 H₂(g)

Quiz 3: Mass Relationships in Chemical Reactions

How many grams of calcium chloride are needed to produce 10.0 g of potassium chloride? CaCl2(aq) + K2CO3(aq) → 2 KCl(aq) + CaCO3(aq)

If the percent yield for the following reaction is 60.0%,and 45.0 g of NO2 are consumed in the reaction,how many grams of nitric acid,HNO3(aq) ,are produced? 3 NO2(g) + H2O(l) → 2 HNO3(aq) + NO(g)

What is the identity of substance X if 0.380 mol of X weighs 17.5 g?

What mass of sulfur hexafluoride,SF6,has the same number of fluorine atoms as 50.0 g of oxygen difluoride,OF2?

Which of the following has the greatest mass?

What is the molar mass of aspirin if 5.19 × 1016 molecules of aspirin weigh 15.53 μg?

When methane,CH4,undergoes combustion with oxygen,the usual products are carbon dioxide and water.Carbon monoxide is formed when the limiting reactant is

How many cations are in 0.500 g of MgBr2?

Balance the chemical equation given below,and determine the number of moles of iodine that reacts with 5.0 g of aluminum. ________ Al(s) + ________ I2(s) → ________ Al2I6(s)

3.0 moles of nitrogen is reacted with 11.0 moles of hydrogen to produce ammonia according to the chemical equation shown below.Which one of the following statements is false? N2(g) + 3 H2(g) → 2 NH3(g)

The density of ethanol,C2H5OH,is 0.789 g/mL.How many milliliters of ethanol are needed to produce 5.00 g of CO2 according to the following chemical equation? C2H5OH(l) + 3 O2(g) → 2 CO2(g) + 3 H2O(l)

Which of the following has the smallest mass?

In the reaction between glucose and oxygen,10.0 g of glucose reacts and 7.50 L of carbon dioxide is formed.What is the percent yield if the density of CO2 is 1.26 g/L? C6H12O6(s) + 6 O2(g) → 6 CO2(g) + 6 H2O(l)

Balance the chemical equation given below,and determine the number of grams of Fe needed to produce 15.0 g of Fe2O3. ________ MgO(s) + ________ Fe(s) → ________ Fe2O3(s) + ________ Mg(s)

How many anions are in 10.0 g of sodium phosphate?

Which of the following has the greatest mass?

5.0 g of nitrogen is reacted with 5.0 g of hydrogen to produce ammonia according to the chemical equation shown below.Which one of the following statements is false? N2(g) + 3 H2(g) → 2 NH3(g)

What mass of carbon monoxide,CO,contains the same number of molecules as 3.00 g of trichlorofluoromethane,CCl3F?

Tablets of ascorbic acid,or Vitamin C,C6H8O6,are taken as a dietary supplement.If a typical tablet contains 500 mg,how many molecules of Vitamin C are in a tablet?

4.0 g of iron is reacted with 4.0 g of water according to the chemical equation shown below.Which one of the following statements is false? 3 Fe(s) + 4 H2O(l) → Fe3O4(s) + 4 H2(g)

How many grams of calcium chloride are needed to produce 10.0 g of potassium chloride? CaCl₂(aq) + K₂CO₃(aq) → 2 KCl(aq) + CaCO₃(aq)

If the percent yield for the following reaction is 60.0%,and 45.0 g of NO₂ are consumed in the reaction,how many grams of nitric acid,HNO₃(aq) ,are produced? 3 NO₂(g) + H₂O(l) → 2 HNO₃(aq) + NO(g)

What mass of sulfur hexafluoride,SF₆,has the same number of fluorine atoms as 50.0 g of oxygen difluoride,OF₂?

What is the molar mass of aspirin if 5.19 × 10¹⁶ molecules of aspirin weigh 15.53 μg?

When methane,CH₄,undergoes combustion with oxygen,the usual products are carbon dioxide and water.Carbon monoxide is formed when the limiting reactant is

How many cations are in 0.500 g of MgBr₂?

Balance the chemical equation given below,and determine the number of moles of iodine that reacts with 5.0 g of aluminum. Al(s) + I₂(s) → Al₂I₆(s)

3.0 moles of nitrogen is reacted with 11.0 moles of hydrogen to produce ammonia according to the chemical equation shown below.Which one of the following statements is false? N₂(g) + 3 H₂(g) → 2 NH₃(g)

The density of ethanol,C₂H₅OH,is 0.789 g/mL.How many milliliters of ethanol are needed to produce 5.00 g of CO₂ according to the following chemical equation? C₂H₅OH(l) + 3 O₂(g) → 2 CO₂(g) + 3 H₂O(l)

In the reaction between glucose and oxygen,10.0 g of glucose reacts and 7.50 L of carbon dioxide is formed.What is the percent yield if the density of CO₂ is 1.26 g/L? C₆H₁₂O₆(s) + 6 O₂(g) → 6 CO₂(g) + 6 H₂O(l)

Balance the chemical equation given below,and determine the number of grams of Fe needed to produce 15.0 g of Fe₂O₃. MgO(s) + Fe(s) → Fe₂O₃(s) + Mg(s)

5.0 g of nitrogen is reacted with 5.0 g of hydrogen to produce ammonia according to the chemical equation shown below.Which one of the following statements is false? N₂(g) + 3 H₂(g) → 2 NH₃(g)

What mass of carbon monoxide,CO,contains the same number of molecules as 3.00 g of trichlorofluoromethane,CCl₃F?

Tablets of ascorbic acid,or Vitamin C,C₆H₈O₆,are taken as a dietary supplement.If a typical tablet contains 500 mg,how many molecules of Vitamin C are in a tablet?

4.0 g of iron is reacted with 4.0 g of water according to the chemical equation shown below.Which one of the following statements is false? 3 Fe(s) + 4 H₂O(l) → Fe₃O₄(s) + 4 H₂(g)