How can you detect that a chemical reaction has occurred? select all that apply

The clouds are grey and ground is wet. a quantitative b qualitative

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?

0.2348 grams of pbcl2 used to form 44.0 ml of solution.