Mass Concentration of Solutions

What is the percentage concentration in the following solution given 2g sucrose in 80g water?

• 2.4%

• 2.5%

• 4.0%

• 97.6%

Sterling silver contains 95% silver. If a necklace made of sterling silver weighs 15g, what is the mass of the silver dissolved in the necklace?

• 1.6g

• 6.2g

• 9.0g

• 14.25g

What is the percent by mass concentration of a solution that contains 6.0g of sugar dissolved in 20.7g of water?

• 21.21%

• 22.21%

• 22.47%

• 22.74%

Brass is a copper- zinc alloy. If the concentration of zinc is relatively low, the brass has a golden color and is often used for inexpensive jewelry. If a 35.0g pendant contains 1.7g of zinc, what is the % by mass of zinc in brass?

• 4.61%

• 4.70%

• 4.85%

• 10%

Tags

NGSS.MS-PS1-1

A solution of benzene and toluene was prepared by adding toluene to benzene until the total volume becomes 135mL. By volume, the solution is 30.0% benzene. How much benzene, in mL, is in the solution?

• 39.5mL of benzene

• 40.5mL of benzene

• 41.5mL of benzene

• 42.5mL of benzene

A solution is prepared by mixing a 20g of sodium chloride in 80g of water. What are the concentrations of the solute and solvent in % by mass?

• Solute: 10% ; Solvent: 90%

• Solute: 20% ; Solvent: 80%

• Solute: 30% ; Solvent: 70%

• Solute: 40% ; Solvent: 60%

What is the volume of a 25% methyl solution that contains 20mL of methyl?

• 6.25mL

• 7.25mL

• 8.25mL

• 9.25mL

You bought an 18 karats ring which contains 18g of gold. What is the % by mass of gold in a ring?

• 65%

• 75%

• 85%

• 95%

What is the % (m/m) if 10.0g of copper is added to enough zinc to produce 110g of an alloy?

• 9.05%

• 9.09%

• 9.10%

• 10.00%

How many grams of glucose are needed to prepare 400mL of 5% glucose solution?

• 5g

• 10g

• 14g

• 20g