ConcentationCalculations

Calculate the moles of 0.195 g of cholesterol, C₂₇H₄₆O.

• 0.505 mol

• 0.505 mmol

• 386 mol

• 75.3 mol

Calculate the molarity of 0.195 g of cholesterol, C₂₇H₄₆O, in 0.100 L of serum, the average concentration of cholesterol in human serum.

• 5.04 mM

• 5.04 M

• 1.95 M

• 3.86 M

The density of human blood serum is 0.994 g/mL. What is the percent by mass concentration of cholesterol in blood?

• 0.196 m/m%

• 0.193 m/m%

• 0.994 m/m%

• 1.95 m/m %

Calculate the number of moles and the mass of the solute in the following solution: 5.50 L of 13.3 M H₂CO, the formaldehyde used to “fix” tissue samples

• 73.2 mol, 2.20 kg

• 73.2 mol, 2.438 g

• 0.413 mol, 12.4 g

• 73.2 mol, 2.40 kg

0.2074 g of calcium hydroxide, Ca(OH)₂, in 40.00 mL of solution - what is the molarity of the solution?

• 2.80 mmol/L

• 0.0701 mol/L

• 0.0910 mol/L

• 0.136 mol/L

What mass of a concentrated solution of nitric acid (68.0% HNO₃ by mass) is needed to prepare 400.0 g of a 10.0% solution of HNO₃ by mass?

• 40.0 g

• 58.8 g

• 5.88 g

• 17.0 g

What mass of a 4.00% NaOH solution by mass contains 15.0 g of NaOH?

• 375 g

• 60.0 g

• 0.600 g

• 150 g

What mass of solid NaOH is required to prepare 1.00 L of a 10.0% solution of NaOH by mass? The density of the 10.0% solution is 1.109 g/mL.

• 114 g

• 100 g

• 90.2 g

• 110.9 g

Copper(I) iodide (CuI) is often added to table salt as a dietary source of iodine. How many moles of CuI are contained in 454 g of table salt containing 0.0100% CuI by mass?

• 0.0454 mol

• 45.4 mmol

• 0.238 mmol

• 8.65 mmol

A throat spray is 1.40% by mass phenol, C₆H₅OH, in water. If the solution has a density of 0.9956 g/mL, calculate the molarity of the solution. (Hint: let's take, for example, 100 g solution.)

• 14.9 mol/L

• 0.148 mol/L

• 0.139 mol/L

• 1.38 mol/L