Question

8. Describe exactly how you would make 100 grams of a saltwater solution that is 20 percent salt. In your description, tell how many grams of salt and how many grams of water you would need.

Answer 1

To create 100 grams of a 20% salt water solution, weigh out 20 grams of salt and add this to 80 grams of water, making sure the total mass adds up to 100 grams. The percent by mass of the solution is used to determine these amounts.

Step-by-step explanation:

To make 100 grams of a saltwater solution that is 20 percent salt, you would need 20 grams of salt and 80 grams of water. This is because 20 percent of the total mass of the solution (which is 100 grams) must be salt.

Hence, the calculation for the mass of salt is (20/100) × 100 grams = 20 grams.

To find the mass of water, you subtract the mass of salt from the total mass of the solution: 100 grams - 20 grams = 80 grams of water.

Percent by mass is the common way of representing the concentration of a solution. In this case, 20 grams of salt is 20 percent by mass of the 100-gram solution.

You would first weigh out 20 grams of salt (NaCl), then add this to 80 grams of water to obtain the desired solution.

Do remember that when preparing solutions, always add the solute (salt) to the solvent (water).