Please make sure it is correct.
Fish tank water must be kept at a particular pH level so the fish stay healthy. What is the best way to protect the water from becoming too acidic or too basic?

a) Add a buffer to the water

b) Put pH paper on the tank.

c) Add acid to the water.

d) Fill the tank with colored water.

What is the measure of how much matter is in an object and that can be measured using a balance? a. height b. volume c. weight d. mass

An insulated thermos contains 148 g of water at 72.7 ˚c. you put in a 11.7 g ice cube at 0.00 ˚c to form a system of ice + original water. the specific heat of liquid water is 4190 j/kg•k; and the heat of fusion of water is 333 kj/kg. what is the net entropy change of the system from then until the system reaches the final (equilibrium) temperature?

How much energy will be transferred to your eardrum while listening to this sound for 1.0 min?