Chemistry Answers

1. A chemistry student added 22.5 grams of aluminum at 85.00C to 115 grams of water at 23.00C in a perfect calorimeter. The final temperature of the aluminum-water mixture was 41.40C. Use the student’s data to calculate the specific heat of aluminum in joules/gram0C.

2. Calculate the final temperature that results from mixing 100.0 grams of water at 1000C with 106.0 grams of water at 24.80C

A sample of gas has a mass of 38.7 mg. Its volume is 220 mL at a temperature of 54 ∘C and a pressure of 897 torr. Find the molar mass of the gas. Express your answer in grams per mole to three significant figures. 

At certain temperature a 1.0 L flask initially contained 0.298mol PCl3(g) and 8.7 x 10-3 mol PCl5(g). After the system had reached equilibrium, 2.00 x 10-3 mol Cl2(g) was found in the flask. Gaseous PCl5(g) decomposes according to the reaction:

   PCl5(g)                    PCl3(g) + Cl2(g)

Calculate the equilibrium concentration of all species and the value of K.

The reaction will proceed in the forward direction

A mixture of CH4 and H2O is passed over a nickel catalyst at 1000K. The emerging gas is collected in a 5.00L flask and is found to contain 8.62g of CO, 2.60g of H2, 43.0g of CH4 and 48.4g of H2O. Assuming that equilibrium has been reached, calculate Kc and Kp for the reaction.

2N_{2 (g)} +5O_{2 (g)} +2H₂ O_(l)  4HNO_{3 (aq)}, ΔH₁ = -255 kJ

Η_{2 (g)} + 1/2O_{2 (g)} H₂O_{( l)}, ΔH₂ = - 256 kJ

S_(s) + H_{2 (g)} +2O_{2 (g)}  H₂SO_{4 (aq)}, ΔH₃ = - 814 kJ

N_{2 (g)} + 2O_{2 (g)}  2NO_{2 (g)}, ΔH₄ = +66 kJ

Να υπολογίσετε την πρότυπη ενθαλπία της αντίδρασης:

6HNO _(aq) + S_(s)  H₂ SO_{4 (aq)} 6NO _(g) 2H₂ O _{(l )}

The current price of pure gold is $45.00 per gram.  A jewelry dealer offers to pay Jemma $600 for her solid gold ring which is composed of 3.67x1022 atoms of gold.  Is this a good deal (for Jemma)? Show your work to explain your reasoning.

5 sigma bonds

Calculate the chemical shift in ppm for s proton that has resonance 128 hz downfield from a TMS on a spectrometer that operates at 60 MHz

Identify the number of terminal CO ligands in [(η5–C5H5)Re(CO)x]2, which has aRe-Re single bond and onebridgedCO

The molality of 0.05 mol hcl in 5 litre solution at 4°c