How much energy is needed to turn 233.0g of 0°C liquid water in to 0°C ice?

If you add 5.00 ml of 0.100 m sodium hydroxide to 50.0 ml of acetate buffer that is 0.100 m in both acetic acid and sodium acetate, what is the ph of the resulting solution? acetic acid: ka = 1.8. x 10-5

Calculate the number of kilojoules to warm 125 g of iron from 23.5°c to 78.0°c.

The volume of an unknown substance in a sealed glass jar is 50 milliliters. the volume of the jar is 200 milliliters. which state of matter could the substance be?