Question

22. What is the correct name of the following structural formula? На Н,с CH3 a) methyl propanoate b) ethyl methanoate c) ester butanoate d) propyl methanoate e) methyl ethanoate 23. How much energy is required to convert 10.0 g of ice at 0 °C into steam a) 30.1 kJ b) 22600 J c) 4.180 kJ Plesse inchde you cwhat' d) 3330 J e) 25.9 kJ you dibe - And cuhp certain answers wreng are Page 6 of 7

Answer 1

PART 22:

На .C. °. -methyl (Н,с CH3 propånoate

The given compound is an ester.

In this case, H from -COOH group is replaced by another group. Here it is a methyl group.

The alkyl group along with the -COO group is given a suffix oate.

Hence the given compound is methyl propanoate.

• So the correct option is (a) methyl propanoate.

PART 23:

Total energy required = (energy required for melting) + (energy required to rise the temperature of water from 0^oC to 100^oC) + (Energy required for vaporization).

$\small H=H_{melting}+H_{\Delta T}+H_{vap}$

$\small H=(L_{f}m)+(mc\Delta T)+(L_{v}m)$

Where we have:

Mass of water/ice, m = 10 g

Latent heat of fusion of ice, L_f = 334 J/g

Specific heat capacity of water, C = 4.184 J/g.^oC

Change in temperature, ΔT = 100^oC - 0^oC = 100^oC

Latent heat of vaporization, L_v = 2256 J/g

Hence total energy required:

$\small H=(334\times 10)+(10\times4.184\times100)+(2256\times 10)$

HE 30084 E 30.084 KJ

$\small \boldsymbol{\therefore H\approx 30.1\;kJ}$

• So the correct option is (a) 30.1 kJ

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