A sample of sodium chloride was found to contain 60.66 g of sodium and 39.34 g of chloride. How many grams of each element would be expected in a 200.0 g sample of sodium chloride?

78.68g Na

121.32 Cl

Explanation:

This one is more easy than the wording makes it seem. Since there are 60.66g of sodium (Na) and 39.34g of Chlorine (Cl) it adds up to 100g, so in this case you can just double each amount, and get what each would be in a 200g sample.

when [oh-] is 10-5  m, and [h3o+] is 10-9  m, the poh is 5 and ph is 9. again in both cases the sum of ph and poh is 14. however, the hydrogen ion concentration is not always going to be equal to exactly 1 x 10 raised to a negative number. for example, we skipped over the value of 2.0 x 10-7.