Physical Chemistry Answers

A 0.17g sample of a Group 14 chloride, XCl 4, reacted with water to produce an oxide, XO2, and
HCl.
equation 1 XCl 4(s) + 2H2O(l) → XO2(s) + 4HCl (aq)
The HCl produced was absorbed in 100 cm3
of 0.10 mol dm–3 sodium hydroxide solution (an excess).
In a titration, the unreacted sodium hydroxide solution required 30.0 cm3
of 0.20 mol dm–3 hydrochloric
acid for complete neutralisation.
(a) Calculate the amount, in moles, of hydrochloric acid used in the titration to neutralise the
unreacted sodium hydroxide solution.
amount = ............................ mol

A solution containing Na2CO3 and NaOH
requires 300 mL of 0.1 N HCl using phenol-
phthalein as in indicator. Methyl orange is
then added to above titrated solution when a
further 25 mL of 0.2 NHCl is required. The
amount of NaOH present in solution is
[NaOH = 40, Na2CO3 = 106]
(a) 0.8 g (b) 1.0 g
(c) 1.5 g (d) 2.0 g

Estimate the standard molar enthalpy of vaporization of bromine at 59.2 degree celcius

Explain in brief why is the hydride bridge in (BeH2)n considered to be electron deficient but not the chloride bridge in (BeCl2)n.

How many grams of na2co3.10h20 need to prepare 1.5l of 5%weight na2co3 (density is 1.2g/ml)

One mole of an ideal gas with CV = 3/2R undergoes the transformations described in the following list from an initial state described by T = 300 K and P = 1.00 bar. ΔΗ can be calculated with the following equation if the gas is heated to 450 K at a constant external pressure of 1.00 bar

For a reaction in equilibrium at temperature T0, show that if the reaction is endothermic, heating to a higher temperature T1 causes some reactant to spontaneously convert to product, by making use of the integrated Gibbs-Helmholtz equation

Given that the molar volume change on melting ice is -1.56 cm3
mol -1,the molar enthalpy of fusion is 6.030 kJ mol-1, and the melting temperature of ice at atmospheric pressure (105 Pa) is 273.15 K,
calculate the melting temperature of ice at a pressure of 7 MPa.

Solubilty of NHCH3+ group in
1- water
2- pH =7
3- excess OH-

An object is projected with an initial speed of 24 ms-1 at an angle of 40° above the horizontal. The object hits the ground at point B. If the distance from A to B is 57 m, and taking g —— 9.81 ms-2, calculate the following:
i) the time taken for the object to move from A to B;
ii) the height h,
iii) the final speed of the object at point B;
iv) the angle c‹.