What is the percentage error for a mass measurements of 17.7 g? given that the correct value is 21.2g

Which compound contains both ionic and covalent bonds? a) hbr b)cbr4 c)nabr d) naoh

Suppose you wanted to make 100 grams of water. what is the molar mass of water (h2o)?

Hydrogenation reactions, in which h2 and an "unsaturated" organic compound combine, are used in the food, fuel, and polymer industries. in the simplest case, ethene (c2h4) and h2 form ethane (c2h6). if 140 kj is given off per mole of c2h4 reacting, how much heat (in mj) is released when 12 kg of c2h6 forms?