Question

1. True or False. When 1.00 L of a NaCl solution is diluted to 1.80 L, the number of moles of NaCl is the same in both solutions.

2. True or False. When 1.00 L of a NaCl solution is diluted to 1.80 L, the mass of NaCl increases.

3. True or False. When 1.00 L of a NaCl solution is diluted to 1.80 L, the concentration of NaCl increases.

4. True or False. When 1.00 L of a NaCl solution is diluted to 1.80 L, the number of moles of NaCl decreases.

Answer 1

When 1.00 L of a NaCl solution is diluted to 1.80 L ,The number of moles always stays the same in a dilution.The concentration and the volumes change in a dilution.

1. When 1.00 L of a NaCl solution is diluted to 1.80 L, the number of moles of NaCl is the same in both solutions.

ans. True

2. When 1.00 L of a NaCl solution is diluted to 1.80 L, the mass of NaCl increases.

ans. False. Because if the number of moles always stays the same in a dilution,the mass of NaCl also stays the same.

No of moles of NaCl = ( mass of NaCl ) / ( molar mass of NaCl )

3.  When 1.00 L of a NaCl solution is diluted to 1.80 L, the concentration of NaCl increases.

ans. False . Because the the concentration decreases with the increasing of volume of the solution.

4. When 1.00 L of a NaCl solution is diluted to 1.80 L, the number of moles of NaCl decreases.

ans. False. When 1.00 L of a NaCl solution is diluted to 1.80 L, the number of moles of NaCl is the same in both solutions.