Lead has a molar heat capacity of 26.4 J/K•mol. What molar enthalpy change occurs when lead is cooled from 302°C to 275°C?

metal X =51.0g; specific heat capacity =0.44 J/C If metal X is heated to 86C and put into a calorimeter containing water (she=4.18 J/g°C ) at 23C. The final temperature of the water becomes 31C.   What is the mass of water?

the molar heat capacity of iron is 25.10 J mol –1 K–1 . A 25.0 g ball is heated until it is glowing red (to a temperature of 400.°C). It is dropped into a 50.0 mL container of water at 25.0°C. If the density of water is 0.997 g mL–1 , and the molar heat capacity of water is 4.186 J g–1 K–1 , what temperature (in K) will the ball and water equilibrate to? A) 338 B) 300 C) 317 D) 359 E) 342

When a student mixes 50 mL of 1.0 M HCl and 50 mL of 1.0 M NaOH in a coffee-cup calorimeter, the temperature of the resultant solution increases from 21.0°C to 27.5°C. calculate the enthalpy change for the reaction in kJ/mol HCl, assuming that the calorimeter loses only a negligible quantity of heat, that the total volume of the solution is 100 mL, that its density is 1.0 g/mL, and that its specific heat is 4.18 J/g•K. O -27000 J O 54 kJ O 2.7 kJ O -54 kJ

If 30.5 g of LiBr are dissolved 350.0 g of water at 20.0 °C in an insulated container, a temperature change is observed. The Δ H of solution of LiBr is -48.8 kJ/mol. Assuming that the specific heat of the solution is 4.184 J/(g C) and that no heat is gained or lost by the container, what will be the final temperature of the solution?

A piece of chromium metal with a mass of 24.50 g is heated in boiling water to 98.3 °C and then dropped into a coffee-cup calorimeter containing 82.3 g of water at 23.4 °C. When thermal equilibrium is reached, the final temperature is 25.7 °C. Calculate the specific heat capacity of chromium. (The specific heat capacity of liquid water is 4.184 J/g ⋅ K.)

When 14.2 g KBr is dissolved in 100.0 g of water in a coffee-cup calorimeter, the temperature drops from 28.88 °C to 23.38 °C. What is the enthalpy change per gram of KBr dissolved in the water? Assume that the solution has a specific heat capacity of 4.18 J/g·K.

Solid calcium chloride dissolves in water according to the equation below.CaCl2 (s) ➝ Ca+2 (aq) + 2 Cl – (aq)      ΔHº = –81.3 kJ/mol8.00 grams of solid CaCl2 dissolves in 45.0 grams of water initially at a temperature of 20.00 ºC in a perfect calorimeter. Calculate the final temperature of the solution in the calorimeter.[You may assume that no heat escapes the calorimeter and that all solutions have the same specific heat capacity as pure water (4.184 J/g·ºC)]Tfinal = Answer ºC

5.00 × 10−2 mol KOH and an excess of hydrochloric acid are combined in 100.0 mL of water initially at 25.0 °C, leading to a final measured temperature of 31.1 °C. (a) What is the heat flow for the water in the calorimeter, qH2O, in Joules? (b) Assuming the calorimeter constant Ccal = 50.0 J °C , what is the heat flow for the calorimeter, qcal, in Joules? (c) What is the amount of heat given off by the reaction, qrxn, in Joules? (d) What is the molar enthalpy of the neutralization reaction (shown below) as measured in the calorimeter, ∆H◦ rxn in kilojoules per mole? H3O + (aq) + OH– (aq) → 2H2O (l)

A chemist carefully measures the amount of heat needed to raise the temperature of a 0.34 kg sample of C,H¸0 from -1.5 °C to 18.1 °C. The experiment shows that 1.09 × 10* J of heat are needed. What can the chemist report for the molar heat capacity of C,H,O? Round your answer to 2 significant digits. J• mol -1 1 ·K x10