Question 1

An experiment requires 15.0 mL of a 0.100 M solution of HCl. If you have a 12.0 M HCl stock solution in the laboratory, how would you prepare enough 0.1 M solution to run at least 3 experiments?

Accepted Answer

To prepare a 0.1 M solution from a 12 M stock solution, use the dilution formula $C_1V_1 = C_2V_2$. For three experiments, you need $15.0 \, \text{mL} \times 3 = 45.0 \, \text{mL}$ of 0.1 M solution. Using the formula with $C_1 = 12.0 \, \text{M}$, $V_1 = ?$, $C_2 = 0.1 \, \text{M}$, and $V_2 = 45.0 \, \text{mL}$, you find $V_1 = 0.375 \, \text{mL}$. However, the options seem to suggest preparing more than needed for exactly three experiments, likely to ensure there's enough solution accounting for potential inaccuracies or additional volume needed. Option A correctly dilutes a portion of the 12 M HCl stock solution to achieve a 0.1 M solution by adding it to approximately 99.167 mL of water, which aligns with the principle of dilution despite the initial calculation being for exactly three experiments.

Question 2

What is the molar mass of NH₄)₃PO₄?

Accepted Answer

The molecular formula given is for sodium hydrogen sulfate (NaHSO4). The molar mass is calculated as follows: Na (22.99) + H (1.01) + S (32.06) + 4*O (4*16.00) = 22.99 + 1.01 + 32.06 + 64.00 = 120.06 g/mol, which rounds to 121 g/mol, indicating a mistake in the interpretation of the choices. The correct calculation aligns closest with option B, not C, based on standard atomic weights.

Question 3

What is the molar mass of potassium nitrate?

Accepted Answer

Potassium nitrate (KNO3) has a molar mass calculated by adding the atomic masses of potassium (K = 39.10 g/mol), nitrogen (N = 14.01 g/mol), and three oxygen atoms (O = 16.00 g/mol each, totaling 48.00 g/mol). The sum is 39.10 + 14.01 + 48.00 = 101.11 g/mol, which rounds to 101.10 g/mol.

Question 4

What is the mass in grams of 6.022 x 10²³ molecules of CO₂?

Accepted Answer

The given number of molecules is Avogadro's number (6.022 x 10^23), which represents one mole of any substance. The molecular weight of CO2 (carbon dioxide) is approximately 44 g/mol (12 for carbon and 16 for each of the two oxygens). Therefore, one mole of CO2 weighs 44 grams.

Question 5

What is the mass in grams of 1.59 moles of aluminum oxide?

Accepted Answer

The molar mass of aluminum oxide (Al2O3) is approximately 101.96 g/mol. To find the mass of 1.59 moles, multiply the number of moles by the molar mass: 1.59 moles * 101.96 g/mol = approximately 162 grams.

Question 6

What is the molar mass of K₂CO₃?

Accepted Answer

The molar mass of K2CO3 is calculated by adding the atomic masses of 2 potassium (K) atoms, 1 carbon (C) atom, and 3 oxygen (O) atoms: (2*39) + 12 + (3*16) = 138 g/mol.

Question 7

A 44.8 g rhodium sample contains how many rhodium atoms?

Accepted Answer

To find the number of rhodium atoms in a 44.8 g sample, use Avogadro's number (6.02 x 10^23 atoms/mol) and the molar mass of rhodium (102.91 g/mol). The calculation is (44.8 g / 102.91 g/mol) * (6.02 x 10^23 atoms/mol) = 2.62 x 10^23 atoms.

Question 8

To dilute a HCl solution from 0.500 M to 0.100 M the final volume must be:

Accepted Answer

To dilute a solution, the final volume must be greater than the initial volume. Using the dilution formula M1V1 = M2V2, where M1 is the initial concentration, V1 is the initial volume, M2 is the final concentration, and V2 is the final volume, it's clear that to decrease the concentration from 0.500 M to 0.100 M, the final volume must be 5 times the original volume (since 0.500/0.100 = 5).

Question 9

What is the mass in grams of 0.852 moles of ferric oxide?  Paired item 1)

Accepted Answer

The answer of What is the mass in grams of...

Question 10

How many grams are in 1.02 x 10²² molecules of nitric acid? Paired item 1)

Accepted Answer

To find the mass in grams, first convert molecules to moles using Avogadro's number (6.022 x 10^23 molecules/mol), then multiply by the molar mass of nitric acid (HNO3, approximately 63.01 g/mol).

Question 11

What is the total number of atoms contained in 2.11 moles of nickel?

Accepted Answer

The total number of atoms in a mole is given by Avogadro's number, which is approximately 6.022 x 10^23 atoms/mole. Therefore, 2.11 moles of nickel contains 2.11 x 6.022 x 10^23 = 1.27 x 10^24 atoms.

Question 12

How many grams are in 2.05 x 10²³ molecules of dinitrogen pentoxide?

Accepted Answer

To find the mass in grams, first convert molecules to moles using Avogadro's number (6.022 x 10^23 molecules/mol), then multiply by the molar mass of dinitrogen pentoxide (N2O5), which is approximately 108 g/mol.

Question 13

Which of the following compounds contains the largest number of atoms?

Accepted Answer

The answer of Which of the following compounds contains the...

Question 14

What is the total number of atoms contained in 1.00 mole of sodium?

Accepted Answer

The total number of atoms in 1.00 mole of any substance is given by Avogadro's number, which is 6.02 x 10^23 atoms.

Question 15

If a hazardous bottle is labeled 20.2 percent by mass Hydrochloric Acid, HCl, with a density of 1.096 g/mL, calculate the molarity of the HCl solution.

Accepted Answer

To calculate the molarity of the HCl solution, first, determine the mass of HCl in 1000 mL of solution. Since the solution is 20.2% HCl by mass, 1000 mL of this solution (with a density of 1.096 g/mL) has a mass of 1096 g, and 20.2% of this mass is HCl: $1096 g \times 0.202 = 221.392 g$ of HCl. The molar mass of HCl is approximately 36.46 g/mol, so the number of moles of HCl in 1000 mL of solution is $221.392 g \div 36.46 g/mol = 6.07$ moles. Since molarity is moles of solute per liter of solution, the molarity of the HCl solution is 6.07 M.

Question 16

How would you prepare a 1 M solution of sodium hydroxide?

Accepted Answer

The molar mass of sodium hydroxide (NaOH) is approximately 40.0 g/mol. To prepare a 1 M solution, you need to dissolve 40.0 grams of NaOH in enough water to make the total volume 1 liter, as per option A.

Question 17

How many atoms are in 1.00 mole of Au?  Paired item 1)

Accepted Answer

The number of atoms in 1.00 mole of any substance is defined by Avogadro's number, which is 6.02 x 10^23 atoms.

Question 18

How many moles are in 1.77 kg of cuprous sulfate?

Accepted Answer

To find the number of moles in 1.77 kg of cuprous sulfate (Cu2SO4), first convert the mass to grams (1.77 kg = 1770 g). The molar mass of Cu2SO4 is approximately 223.15 g/mol. Using the formula moles = mass (g) / molar mass (g/mol), we get moles = 1770 g / 223.15 g/mol ≈ 7.93 moles.

Question 19

What is the total number of atoms contained in 2.00 moles of iron?

Accepted Answer

The total number of atoms in 2.00 moles of iron is calculated using Avogadro's number (6.022 x 10^23 atoms/mole). Therefore, 2.00 moles of iron contain 2.00 x 6.022 x 10^23 = 1.2 x 10^24 atoms.

Question 20

How would you prepare a 0.5 M solution of sodium hydroxide?  Paired item 1)

Accepted Answer

To prepare a 0.5 M solution of sodium hydroxide (NaOH), you need to know the molar mass of NaOH, which is approximately 40.0 g/mol. For a 0.5 M solution, you need 0.5 moles of NaOH per liter of solution. Therefore, 0.5 moles * 40.0 g/mol = 20.0 grams of NaOH should be dissolved in 1 liter of water.

Quiz 3: Composition of Substances and Solutions

An experiment requires 15.0 mL of a 0.100 M solution of HCl. If you have a 12.0 M HCl stock solution in the laboratory, how would you prepare enough 0.1 M solution to run at least 3 experiments?

What is the molar mass of NH₄) ₃PO₄?

What is the molar mass of potassium nitrate?

What is the mass in grams of 6.022 x 10²³ molecules of CO₂?

What is the mass in grams of 1.59 moles of aluminum oxide?

What is the molar mass of K₂CO₃?

A 44.8 g rhodium sample contains how many rhodium atoms?

To dilute a HCl solution from 0.500 M to 0.100 M the final volume must be:

What is the mass in grams of 0.852 moles of ferric oxide? Paired item 1)

How many grams are in 1.02 x 10²² molecules of nitric acid? Paired item 1)

What is the total number of atoms contained in 2.11 moles of nickel?

How many grams are in 2.05 x 10²³ molecules of dinitrogen pentoxide?

Which of the following compounds contains the largest number of atoms?

What is the total number of atoms contained in 1.00 mole of sodium?

If a hazardous bottle is labeled 20.2 percent by mass Hydrochloric Acid, HCl, with a density of 1.096 g/mL, calculate the molarity of the HCl solution.

How would you prepare a 1 M solution of sodium hydroxide?

How many atoms are in 1.00 mole of Au? Paired item 1)

How many moles are in 1.77 kg of cuprous sulfate?

What is the total number of atoms contained in 2.00 moles of iron?

How would you prepare a 0.5 M solution of sodium hydroxide? Paired item 1)

Quiz 3: Composition of Substances and Solutions

An experiment requires 15.0 mL of a 0.100 M solution of HCl. If you have a 12.0 M HCl stock solution in the laboratory, how would you prepare enough 0.1 M solution to run at least 3 experiments?

What is the molar mass of NH4) 3PO4?

What is the molar mass of potassium nitrate?

What is the mass in grams of 6.022 x 1023 molecules of CO2?

What is the mass in grams of 1.59 moles of aluminum oxide?

What is the molar mass of K2CO3?

A 44.8 g rhodium sample contains how many rhodium atoms?

To dilute a HCl solution from 0.500 M to 0.100 M the final volume must be:

What is the mass in grams of 0.852 moles of ferric oxide? Paired item 1)

How many grams are in 1.02 x 1022 molecules of nitric acid? Paired item 1)

What is the total number of atoms contained in 2.11 moles of nickel?

How many grams are in 2.05 x 1023 molecules of dinitrogen pentoxide?

Which of the following compounds contains the largest number of atoms?

What is the total number of atoms contained in 1.00 mole of sodium?

If a hazardous bottle is labeled 20.2 percent by mass Hydrochloric Acid, HCl, with a density of 1.096 g/mL, calculate the molarity of the HCl solution.

How would you prepare a 1 M solution of sodium hydroxide?

How many atoms are in 1.00 mole of Au? Paired item 1)

How many moles are in 1.77 kg of cuprous sulfate?

What is the total number of atoms contained in 2.00 moles of iron?

How would you prepare a 0.5 M solution of sodium hydroxide? Paired item 1)

What is the molar mass of NH₄) ₃PO₄?

What is the mass in grams of 6.022 x 10²³ molecules of CO₂?

What is the molar mass of K₂CO₃?

How many grams are in 1.02 x 10²² molecules of nitric acid? Paired item 1)

How many grams are in 2.05 x 10²³ molecules of dinitrogen pentoxide?