Calculate the change in internal enargy when a closed system releases 380 kJ of heat and has 275 kj of work done on it by the surrounding

Avariable that is not being directly tested during an experiment should be

How much heat is added if 0.814g of water increase in temperature by 0.351 degree c?

For a research project, a student decided to test the effect of the lead(ii) ion (pb2+) on the ability of salmon eggs to hatch. this ion was obtainable from the water‐soluble salt, lead(ii) nitrate, which the student decided to make by the following reaction. pbo(s) + 2 hno3(aq) → pb(no3)2(aq) + h2o losses of product for various reasons were expected, and a yield of 86.0% was expected. in order to have 5.00 g of product at this yield, how many grams of pbo should be reacted? (assume that sufficient nitric acid, hno3, would be used.)