Which of the following examples shows that a chemical reaction has occurred? a teeth chop up an apple slice into smaller pieces. b sugar placed in sugar water sinks to the bottom. c a glass jar shatters into many pieces when dropped. d bleach gets rid of a ketchup stain on a white shirt.

Calcium hydride (cah2) reacts with water to form hydrogen gas: cah2(s) + 2h2o(l) → ca(oh)2(aq) + 2h2(g) how many grams of cah2 are needed to generate 45.0 l of h2 gas at a pressure of 0.995 atm and a temperature of 32 °c?

What is the volume of the fluid in the graduated cylinder with accuracy and measured to the correct degree of precision? 41.2 ml 42.0 ml 41.23 ml 41.89 ml

The covalent compound acetylene, which is the fuel of the oxyacetylene torch used by welders, has the molecular formula c2h2. the covalent compound benzene, a commercial solvent, has the molecular formula c6h6 each of these covalent compounds contains carbon and hydrogen atoms in a one-to-one ratio. would it be correct to write the chemical formulas of each as ch? explain.