General Chemistry Answers

Bromination of cyclopropene give what? a) 1,1-dibromocyclopropane b) 1,2-dibromocyclopropane c) bromocyclopropane d) negative

Passing acetylene in a red hot nickel tube, followed by chlorination of the organic product, then bromination give ..... a)Benzene b) 1-bromo-2-chlorobenzene c) 1-bromo-3-chlorobenzene d) 1-bromo-4-chlorobenzene e) both b and d

Which electron configuration represents the electrons of an atom in an excited state?

A)2-7-4

B)2-4

C)2-8-7

D)2-1

A coloured solution is placed within a spectrometer. At 554 nm the solution shows an absorbance of 0.69. Calculate the percentage of light that is being absorbed.

 1)  What is the solubility of PbI₂ in g/l, if the solubility product is 7.9x10^-9

2) Cu(s)/ Cu+2 (0.02M) //Zn2+ (0.02M)/Zn(s); the standard reduction potential for Cu and Zn is 0.34 and -0.76 respectively. Calculate the standard cell potential, change in free energy and cell potential

A coloured solution is placed within a spectrometer. At 554 nm the solution shows an

absorbance of 0.69. Calculate the percentage of light that is being absorbed.

How many moles of NaAlO2 is produced if 126.4 g of NaOH reacts completely?

a 0.010 mole sample of barium nitrate formed was heated until it had completely decomposed according to the following balanced equation.

2Ba(NO₃)₂ =2BaO + 4 NO₂ + O₂

. Using the ideal gass equation to calculate the total volume, cm³ of gaseous product obtained at 387K and 1.12×10⁵ Pa.

What will be the products when ammonia reacts with hydrofluoric acid? In the reaction identify the type of species present (acid, base, conjugate acid/ base).

Read and answer the following problems. Show your solutions.

1. The work done by a system is 8 J, when 40 J heat is supplied to it. What is the

change in internal energy of the system during the process?

2. Given the balanced equation below for the highly exothermic reaction of aluminum

with oxygen to form aluminum oxide:

4Al(s) + 3O2(g)  2Al2O3(s) ∆H = - 1,670 kJ

a. What is the value of ∆H when 2 moles of aluminum react?

b. What is the value of ∆H when 10.8 g of aluminum reacts?

c. A certain reaction releases 6,881 kJ of heat. What mass of aluminum oxide was

produced in the reaction?

3. From the given enthalpies of reaction;

4HCl(g) + O2(g)  2H2O(l) + 2Cl2(g) ∆Hrxn = -202.4kJ/mol

1⁄2 H2(g) + 1⁄2 F2(g) HF(l) ∆Hrxn = -600.0 kJ/mol

H2(g) + 1⁄2 O2 (g)  H2O(l) ∆Hrxn = -285.8 kJ/mol

Find:

∆Hrxn for 2HCl(g) + F2(g)  2HF(l) + Cl2(g)