Physical Chemistry Answers

At 298 K the standard enthalpy of combustion of solid alanine (NH2CH(CH3)COOH (s)) to give CO2 (g), H2O (liq) and N2 (g) is ΔcombH° = -1618 kJ/mol and the standard enthalpy of formation of liquid methylamine (CH3NH2(liq)) is ΔfH° = -47.3 kJ/mol. Calculate ΔrxH° and ΔrxU° at 298 K for the following reaction.
NH2CH(CH3)COOH (s) + 2H2 (g) → CH3NH2 (liq) + CH4 (g) + HCO2H (liq)

3.26 Sodium reacts with 1.14 oxygen. Forming 4.40 sodium oxide
What is the empirical formula of sodium oxide?
Balance the equation.

1. In two experiment 0.36g and 0.71g of chlorine combine with a metal X to give y and z respectively, an analysis show that y and z contain 0.20g and 0.40g of x respectively. verify that this law is constant composition.
2. the ions x- charged and y+ charged on isoelectronic each contain a total of 10 electron. how many protons are in the nuclues of the nutral atoms of x and y respectively

in two experiment 0.36g and 0.71g of chlorine combine with a metal x to give y and z respectively,an anlnsis show that y and z contain 0.20g and 0.40g of x respectively.verify that this law is constant composition

in two experiment 0.36g and 0.71g of chlorine combine with a metal x to give y and z respectively,an anlysis show that y and z contain 0.20g and 0.40g of x respectively.verify that this law is constant composition

The temperature of 15 ml of a strong acid increases by 2 Kelvin when 15 ml of strong base is added to it.If 5 ml of each are mixed temperature should increase by
1)0.6 K
2)0.3 K
3) 2 K
4) 6 K

I have 2 questions about group 1 elements Sodium and Potassium:
1. Why is the drop in 1st ionisation energy greatest between Na and K?
2. Why is Na denser than K?

a solution of 30 percent ethanel by weight (C2H3OH) has a density of 0.96 g/mole of 2.5 celsius find the molality and molarity