You measure the amount of Oxygen released when Hydrogen peroxide is reacts with Sodium Hydroxide. You are measuring a Change Chemical or physical change? No links please

In 1901, thomas edison invented the nickel-iron battery. the following reaction takes place in the battery. fe(s) + 2 nio(oh)(s) + 2 h2o(l) fe(oh)2(s) + 2 ni(oh)2(aq) how many mole of fe(oh)2, is produced when 5.35 mol fe and 7.65 mol nio(oh) react?

Which of the following describes qualitative data? a) recording the temperature of a solid as it is warmed. b) noting the color of a solution as it is heated. c) measuring the volume of an object by water displacement. d) taking the mass of an object using a balance.

Technician a says that you should never jump-start a frozen battery. technician b says that a frozen battery can explode, causing injury, when jump-started. who is correct?