Chemistry Answers

Calculate the AH for the reaction S02)SO3(g) + using these two reactions:

+0 SO,

2(g) 2SO +0. 2(g) 2(g) 2 (g) 2SO3(0)

AH = -296.8 kJ

AH = -197.0 kJ

Calculate the AH for the reaction 2S+20F₂ (a)

+SF) 2 (9)

using the following thermochemical reactions. + 2HF

AH = -277 kJ

AH = -828 kJ

0₂ (9) SO ₂ (0) (g) +4HF OF 2 (0) SF 4 (g) (0) + 2H₂O

AH = -297 kJ

+0₂ 2(g) 2 (g)

1.    The specific heat capacity of zinc is 0.388 J/g.˚C. Calculate the initial temperature of zinc block of mass 38g if the amount of heat supplied to it was 220 J and the maximum temperature reached by the zinc block was 55˚C.

How many moles of pb(no3)2 are required to react with 10 L of 31 m of kcl

2kcl + pb(no3)2 - pbci2 + 2kno3

do not use unit of moles I. Your answer round 3 decimal places

1.5 mol of kcio3 decomposes. How many grams of O2 will be produced

On analysis of ammonium salt of alkanoic acid give 60.5% of carbon, 6.5% of hydrogen. If 0.309g of the salt yielded 0.0313g of Nitrogen. Determine the empirical formula of the salt.

The metal used to recover copper from a solution of copper sulphate is?

A. Na

B. Ag

C. Hg

D. Fe

Please explain reason for the answer also

The molar enthalpy change accompanying the removal of an electron from a gas phase atom or ion in its ground state is called

A. Electron gain enthalpy

B. Ionization enthalpy

C. Enthalpy change

D. Enthalpic gas removal

A 'breath test' used by traffic police to check drunken driving uses?

A. Tumeric on filter paper

B. Silica gel coated with saliva nitrate

C. Potassium permanganate-sulphuric acid

D. Potassium dichromatic-sulphuric acid

Please explain why the answer is D and not C

A solution contains 20g of solute in 180g of solvent. If the solvent is water, what is the concentration of the solution in terms of mass by mass percentage

A. 11.%

B. 22.2%

C. 10%

D. 20%

Please show working