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3 years ago

Select the compound with the lowest lattice energy.

Chemistry

1 answer:

tatyana61 [14]3 years ago

6 0

Answer:

A. CsBr(s)

Explanation:

we will get here compound with the lowest lattice energy

solution

As we know that Lattice energy is always proportional to the charge of ions and it is inversely proportional to the size of ions.

so that by the smallest charge and the largest size give us the lowest lattice energy and that charge and size is express as here as

Charge

Cs (+1), K(+1), Na (+1), Cl(-1), Br(-1), Sr(+2), Ca(+2), O(-2) .......................1

and

Size

Na+ < Ca2+ < K+ < Sr2+ < Cs+, O2- < Cl- < Br- ..........................2

so that here

correct answer is A. CsBr

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Explain why it is important that there be no gaps around the edges of the filter paper during a vacuum filtration

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Vacuum filtration is more efficient and faster than filtration by the gravity method. But the set up of the vacuum filtration must be precise. Vacuum filtration is done under very reduced pressure hence there should be no gaps around the edges of the filter paper. For a vacuum to be effective there must be no hole or gap in the equipment. Under vacuum conditions air is removed and the pressure is lowered. If there is gap then air would be continuously supplied and it would be difficult to remove air completely.

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3 years ago

Menthol, which is present in mentholated cough drops, is an organic compound

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Answer:

The empirical formula is C10H20O

Explanation:

Step 1: Data given

Mass of the sample = 0.2010 grams

Mass of CO2 = 0.5658 grams

Molar mass CO2 = 44.01 g/mol

Mass of H2O = 0.2318 grams

Molar mass H2O = 18.02 g/mol

Atomic mass C = 12.01 g/mol

Atomic mass O = 16.0 g/mol

Atomic mass H = 1.01 g/mol

Step 2: calculate moles CO2

Moles CO2 = 0.5658 gram / 44.01 g/mol

Moles CO2 = 0.01286 moles

Step 3: Calculate moles C

For 1 mol CO2 we have 1 mol C

For 0.01286 moles CO2 we have 0.01286 moles C

Step 4: Calculate mass C

MAss C = 0.01286 moles * 12.01 g/mol

Mass C =0.1544 grams

Step 5: Calculate moles H2O

Moles H2O =0.2318 grams / 18.02 g/mol

Moles H2O = 0.01286 moles

Step 6: Calculate moles H

For 1 mol H2O we have 2 moles H

For 0.01286 moles H2O we have 2*0.01286 = 0.02572 moles H

Step 7: Calculate mass H

Mass H = 0.02572 moles * 1.01 g/mol

Mass H = 0.0260 grams

Step8: Calculate mass O

Mass O = 0.2010 - 0.1544 - 0.0260

Mass O = 0.0206 grams

Step 9: Calculate moles O

Moles O = 0.0206 grams / 16.0 g/mol

Moles O = 0.00129 moles

Step 10: Calculate the mol ratio

We divide by the smallest amount of moles

C: 0.01286 moles / 0.00129 moles = 10

H: 0.02572 moles / 0.00129 moles = 20

O: 0.00129 moles / 0.00129 moles = 1

The empirical formula is C10H20O

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4 years ago

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1. Convert each of the following Celsius temperatures to Kelvin. a) 27°C b) 100°C c) 0°C

valkas [14]

Answer:

a) 300K

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Explanation:

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Answer:

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Explanation:

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