Basic Chemistry Questions?

I am not sure how to do these problems correctly so an explanation would be great :) 1. Potassium oxide reacts violently with water. Which one of the following gives the formula and the bonding for potassium oxide? a. KO, covalent b. KO, ionic c. K2O, covalent d. K2O, ionic e. PtO2, ionic 2. In the... show more I am not sure how to do these problems correctly so an explanation would be great :)

1. Potassium oxide reacts violently with water. Which one of the following gives the formula and the bonding for potassium oxide?
a. KO, covalent
b. KO, ionic
c. K2O, covalent
d. K2O, ionic
e. PtO2, ionic

2. In the combustion analysis of 0.1127 grams of glucose (C6H12O6), what mass, in grams, of CO2 would be produced?

3. 5.00 grams of magnesium bromide are dissolved in 2 liters of water. What is the total number of moles of ions in the resulting solution?

4. The percent yield of a multistep chemical synthesis was 78.5%. If the actual yield was 4.72 grams, what was the theoretical yield?

Thanks so much!
2 answers 2