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3 years ago

32. Calculate How many kilojoules of heat are re-

Chemistry

1 answer:

mart [117]3 years ago

4 0

Answer:

ΔH = 41.7 kj

Explanation:

Given data:

Mass of ethanol = 50 g

Heat required to vaporize = ?

Boiling point of ethanol = 78.3°C

Molar heat of vaporization = 38.6 kj/mol

Solution:

First of all we will calculate the number of moles.

Number of moles = mass / molar mass

Number of moles = 50 g/ 46.07 g/mol

Number of moles = 1.08 mol

ΔH = 38.6 kj/mol ×1.08 mol

ΔH = 41.7 kj

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Calculate the molecular (formula) mass of each compound: (a) iron(ll) acetate tetrahydrate; (b) sulfur tetrachloride; (c) potass

Nutka1998 [239]

Answer:

a) Iron(ll) acetate tetrahydrate: 245,68 g/mol

b) Sulfur tetrachloride: 173,87 g/mol

c) Potassium ermanganate 158,034 g/mol

Explanation:

To solve this kind of exercises you must look for the number of atoms in each molecule first, then look on the periodic table the atom weight and the multiply the atom weight times the quantity of each atom. For instance:

The molecule of Iron(II) acetate itetrahydrate is (CH3COO)2Fe•4H2O, it means that you have:

2 atoms of carbon times the atomic weight of C (12.00g/mol)= 24g

14 atoms of Hidrogen times the atomic weight of H (1,00g/mol)= 14g

6 atoms of Oxigen times the atomic weight of O (16,0g/mol)= 96

2 atoms of Iron times the atomic weight of Fe (55,84g/mol)= 111,68g

At last, you only have to add the results: 24+14+96+11,68= 245,68g/mol. This example was for the first molecule.

See you,

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3 years ago

Difference between hygroscopic and deliquescent substance with of each

iVinArrow [24]

Answer:

The water soluble substance which absorb moisture from the air and then dissolve on the absorbed moisture to change into liquid taste are called deliquescent substances whereas the substances which absorb moisture from air but do not change their state are called hygroscopic substances.

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3 years ago

Read 2 more answers

Can someone please help a girl out and answer this plsss ...need this as soon as posible

Helga [31]

Answer:

the anwser would be B obtain energy

Explanation:

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3 years ago

Help science periodic table

romanna [79]

All the answers are on the actual periodic table. You should never be told to remember it so I think this is a recourse you are allowed to look at whilst doing your homework lol :) all the answers are written on it hope it helps