I need help ASAP my final 20 points

What is the percent composition of ca(oh)2? 37.7% ca, 53.0% o, and 10.3% h 45.5% ca, 38.2% o, and 16.3% h 54.0% ca, 43.0% o, and 2.7% h 64.7% ca, 27.0% o, and 8.3% h

In the experiment you asked to react hydrochloric acid and with sodium hydroxide. when measuring the volume of the reactants, which instrument would give the greatest precision.

All of the following are homogeneous mixtures except a) sugar dissolved in water. b) orange juice. c) coffee with cream. d) household vinegar. e) apple juice