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3 years ago

Calculate the number of molecules in 7 moles of oxygen

Chemistry

1 answer:

Alexxandr [17]3 years ago

3 0

Answer:

4.21

Explanation:

use Avogadro's number

6.023 x 10^23

multiply this by 7 because you want to find 7 moles :

6.023 x 10^23 x 7 = 4.21

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Calculate the molarity of a solution consisting of 25.0 g of KOH in 3.00 L of solution.

melomori [17]

Answer:

0.15M

Explanation:

The equation for molarity is M= n/L. Where "M" is Molarity, "n" is the number of moles of solute, and "L" is the total liters in solution.

You need to calculate the number of moles from the given grams. The molar mass of KOH is (39.098+ 16 +1.008)= 56.106g. To calculate the mols of KOH, $\frac{25.0g}{1}$ × $\frac{1 mol}{56.106g}$ = 0.44558... mol, you see that the grams unit cancel out leaving you with mol as the unit.

The volume is given in L already so no need to do any conversion. M= $\frac{0.4558mol}{3.00L}$ = 0.1485M ≈ 0.15M

5 0

2 years ago

How many electrons does nitrogen (N) need to gain to have a stable outer electron shell

earnstyle [38]

It need "3 electrons" to have a stable electronic configuration.

'cause it has 5 electrons in it's outer shell & every atom needs 8 electrons. So, it requires 3 more!

Hope this helps!

7 0

3 years ago

Read 2 more answers

Determine the molarity of a 6.0 mole% sulfuric acid solution with SG-a 1.07 Note: Atomic Weight: S (32), O 16); H (O)

marin [14]

Answer:

The molarity of a 6.0 mole% sulfuric acid solution is 2.8157 Molar.

Explanation:

Suppose there are 100 moles in solution:

Moles of sulfuric acid = 6% of 100 moles = 6 moles

Mass of 6 moles of sulfuric acid = 6 mol × 98 g/mol=588 g

Moles of water = 100%- 6% = 94%= 94 moles

Mass of water = 94 mol × 18 g/mol = 1692 g

Specific gravity of the solution ,S.G= 1.07

Density of solution = D

$S.G=\frac{D}{d_w}$

$d_w$ = density of water = 1 g/mL

$D=S.G\times d_w=1.07\times 1 g/mL=1.07 g/mL$

Mass of the solution = 588 g + 1692 g = 2280 g

Volume of the solution = V

Volume = $\frac{Mass}{Density}$

$=\frac{2280 g}{1.07 g/mL}=2130.84 mL=2.13084 L$

1 mL = 0.001 L

$Molarity = \frac{n}{V(L)}$

n = number of moles of compound

V = volume of the solution in L

here we have ,n = 6 moles of sulfuric acid

V = 2.13084 L

So, the molarity of the solution is :

$Molarity=\frac{6 mol}{2.13084 L}=2.8157 mol/L$

5 0

3 years ago

how does a decrease in potential energy during a chemical rwaction relate to the temperature of the surroundings

blondinia [14]

Answer: If the potential energy of the reaction system decreases, then kinetic energy in the surroundings increases and the temperature of the surroundings rises

Explanation:

3 0

3 years ago

Complete the sentence

solmaris [256]

Answer:

Explanation:

physical change

5 0

3 years ago

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