All categories

3 years ago

1. Most of the earth's surface is covered with

Chemistry

1 answer:

frozen [14]3 years ago

5 0

Answer: water

Explanation:if you look at a globe most of it is blue and blue on a globe is water so that means water covers most of the earth

You might be interested in

Fill in the blanks to determine the number of protons and electrons in an oxygen ion. (Consult the periodic table to determine t

Arte-miy333 [17]

The answer would be 2

6 0

3 years ago

Read 2 more answers

At 298 K, the osmotic pressure of a glucose solution (C6H12O6 (aq)) is 12.1 atm. Calculate the freezing point of the solution. T

Anarel [89]

<u>Answer:</u> The freezing point of solution is -0.974°C

<u>Explanation:</u>

To calculate the concentration of solute, we use the equation for osmotic pressure, which is:

$\pi=iMRT$

where,

$\pi$ = osmotic pressure of the solution = 12.1 atm

i = Van't hoff factor = 1 (for non-electrolytes)

M = molarity of solute = ?

R = Gas constant = $0.0821\text{ L atm }mol^{-1}K^{-1}$

T = temperature of the solution = 298 K

Putting values in above equation, we get:

$12.1atm=1\times M\times 0.0821\text{ L.atm }mol^{-1}K^{-1}\times 298K\\\\M=\frac{12.1}{1\times 0.0821\times 298}=0.495M$

This means that 0.495 moles of glucose is present in 1 L or 1000 mL of solution

To calculate the mass of solution, we use the equation:

$\text{Density of substance}=\frac{\text{Mass of substance}}{\text{Volume of substance}}$

Density of solution = 1.034 g/mL

Volume of solution = 1000 mL

Putting values in above equation, we get:

$1.034g/mL=\frac{\text{Mass of solution}}{1000mL}\\\\\text{Mass of solution}=(1.034g/mL\times 1000mL)=1034g$

To calculate the number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$

Moles of glucose = 0.495 moles

Molar mass of glucose = 180.16 g/mol

Putting values in above equation, we get:

$0.495mol=\frac{\text{Mass of glucose}}{180.16g/mol}\\\\\text{Mass of glucose}=(0.495mol\times 180.16g/mol)=89.18g$

Depression in freezing point is defined as the difference in the freezing point of pure solution and freezing point of solution.

The equation used to calculate depression in freezing point follows:

$\Delta T_f=\text{Freezing point of pure solution}-\text{Freezing point of solution}$

To calculate the depression in freezing point, we use the equation:

$\Delta T_f=iK_fm$

Or,

$\text{Freezing point of pure solution}-\text{Freezing point of solution}=i\times K_f\times \frac{m_{solute}\times 1000}{M_{solute}\times W_{solvent}\text{ (in grams)}}$

where,

Freezing point of pure solution = 0°C

i = Vant hoff factor = 1 (For non-electrolytes)

$K_f$ = molal freezing point elevation constant = 1.86°C/m

$m_{solute}$ = Given mass of solute (glucose) = 89.18 g

$M_{solute}$ = Molar mass of solute (glucose) = 180.16 g/mol

$W_{solvent}$ = Mass of solvent (water) = [1034 - 89.18] g = 944.82 g

Putting values in above equation, we get:

$0-\text{Freezing point of solution}=1\times 1.86^oC/m\times \frac{89.18\times 1000}{180.16g/mol\times 944.82}\\\\\text{Freezing point of solution}=-0.974^oC$

Hence, the freezing point of solution is -0.974°C

8 0

3 years ago

Use this condensed chemical structure

liberstina [14]

Answer:

number of carbon-carbon single (C - C) bonds: 1

number of carbon-hydrogen single (C H) bonds: 5

number of nitrogen-hydrogen sing le (N H) bonds:2

number of lone pairs: 1

Explanation:

Ethanamine is a colourless gas having a strong 'ammonia- like' odour. It contains the -NH2 group which makes it an amine. It contains one carbon-carbon bond, five carbon-hydrogen bonds and two nitrogen-hydrogen bonds.

Nitrogen, being sp3 hybridized in the compound has a lone pair of electrons localized on one of the sp3 hybridized orbitals of nitrogen while one sp3 hybridized orbital of nitrogen is used to form a carbon-nitrogen bond. The other two sp3 hybridized orbitals on nitrogen are used to form the two nitrogen-hydrogen bonds.

6 0

3 years ago

Which stroke is this describing?

iren2701 [21]

Answer:

C. Compression

Explanation:

"...are compressed."

8 0

3 years ago

Read 2 more answers

In a study of the following reaction at 1200 K it was observed that when the equilibrium partial pressure of water vapor is 15.0