1.which of the following solution is more concentrated?
A.5g of salt in 50ml of water
B.10g of salt in 100ml of water
C.15g of salt in 50 ml of water
D.20g of salt in 100ml of water

2.Complete the analogy:30% by mass____:30% by volume______.
A.30g solute in 70g solution;30ml solute in 70 ml solution
B.30g solute in 100g solvent;30ml solute in 100ml solvent
C.30g solute in 100g solution;30ml solute in 100ml solvent
D.30g solute in 100g solution;30ml solute in 100ml solution

3.All of the following are quantitative description of concentrations EXCEPT one.
A.molarity
B.dilute solution
C.percent by volume
D.parts per million

4.How do you increase the concentration of a solution?
A.add more solute
B.add more water
C lessen the amount of solute
D lessen the amount of solution

5.How many parts of copper and cold are needed to produce a 14 karat(k) jewelry?
A.18 parts is made up of copper and 6 parts is gold
B.6 parts is made up of copper and 18 parts is gold
C.8 parts is made up of copper and 16 parts is gold
D.10 parts is made up of copper and 14 parts is gold​