What kind of charge would the oxygen atom have compared to the hydrogen atoms

Write a hypothesis that answers the lesson question, “while observing a chemical reaction, how can you tell which reactant is limiting? ” hypothesis: if a substance is the limiting reactant, then . . because . .

If anyone would be able to me out with these three questions it would be these are from the chem 2202 course.

When 13.3 g koh is dissolved in 102.7 g of water in a coffee-cup calorimeter, the temperature rises from 21.4 °c to 31.53 °c. what is the enthalpy change per gram of koh (j/g) dissolved in the water? * take the density of water as 1.00 g/ml. * assume that the solution has a specific heat capacity of 4.18 j/g*k. enter to 1 decimal place. do not forget the appropriate sign /(+). canvas may auto-delete the (+) sign