How many moles of sodium cyanide (NaCN) would be needed to produce 4.2 moles of sodium sulfate (Na2SO4)? (4 points)
H2SO4 + 2NaCN → 2HCN + Na2SO4
O 2.1 mol NaCN
O 4.2 mol NaCN
O 8.4 mol NaCN
O 12.0 mol NaCN

Which part of earth’s surface receives the most direct rays from the sun? a) equator b) ocean c) poles d) mountains

Mary is conducting an experiment on how pollution affects plant growth. how can she ensure that her data are reliable?

Asolution is made by dissolving 2.3 moles of sodium chloride (nacl) in 0.155 kilograms of water. if the molal boiling point constant for water (kb) is 0.51 °c/m, what would be the boiling point of this solution? show all the steps taken to solve this problem.