Question 1
What mass of borax [Na
2B
4O
7(H
2O)
10] could be prepared from 25 kg of colemanite ore [Ca
2B
6O
11(H
2O)
5] by a process that is 95% efficient, assuming that no other boron-containing product is formed?
◦ 47 kg
◦ 42 kg
◦ 33 kg
◦ 31 kg
◦ 20 kg
Question 2
What mass of potassium superoxide could be prepared from 15.6 g of potassium metal and excess oxygen?
◦ 37.6 g
◦ 15.6 g
◦ 22.0 g
◦ 28.4 g
◦ 0.399 g