How many moles are in 20 grams of sodium

Which sample of water contains particles having the highest average kinetic energy?

Makovka662 [10]

(1) 25 ml of water at 95 degrees Celsius is your answer. Temperature is the average kinetic energy of the substance that it measures, therefore the highest temperature choice, aka #1, is your answer.

7 0

3 years ago

In each case, calculate the appropriate ratio to show that the information given is consistent with the law of multiple proporti

Alchen [17]

Answer:

(a) 3:2; (b) 2:1

Explanation:

The Law of Multiple Proportions states that when two elements A and B combine to form two or more compounds, the masses of B that combine with a given mass of A are in the ratios of small whole numbers.

That is, if one compound has a ratio r₁ and the other has a ratio r₂, the ratio of the ratios r is in small whole numbers.

(a) Ammonia and hydrazine.

In ammonia, the mass ratio of H:N is r₁ = 0.2158/1

In hydrazine, the mass ratio of H:N is r₂ = 0.1439/1

The ratio of the ratios is:

$r = \dfrac{r_{1}}{r_{2}} = \dfrac{ 0.2158}{0.1439} = \dfrac{1.500 }{1} = \dfrac{2.999}{2} \approx \mathbf{\dfrac{3}{2}}\\\\\text{The relative amounts of H in the two compounds are in the ratio }\boxed{\mathbf{\dfrac{3}{2}}}$

(b) Nitrogen oxides

In nitrogen monoxide, the mass ratio of O:N is r₁ = 1.142/1

In dinitrogen monoxide, the mass ratio of O:N is r₂ = 0.571/1

The ratio of the ratios is:

$r = \dfrac{r_{1}}{r_{2}} = \dfrac{ 1.142}{0.571} = \dfrac{2.000 }{1} \approx \mathbf{\dfrac{2}{1}}\\\\\text{The relative amounts of O in the two compounds are in the ratio }\boxed{\mathbf{\dfrac{2}{1}}}$

8 0

4 years ago

To what volume should 5.0 g of KCl be diluted in order to prepare a 0.15 M solution? L

Nesterboy [21]

Answer:0.45L

Explanation:

molarity=0.15M

Mass=5g

No of moles=mass ➗ molecular mass

Molecular mass of KCL=39.0983x1+35.453x1

Molecular mass of KCL=74.5513

No of moles=5 ➗ 74.5513

No of moles=0.067

Volume in liters=No of moles ➗ molarity

Volume in liters=0.067 ➗ 0.15

Volume in liters=0.45L

7 0

3 years ago

The chemical mixture that composes our atmosphere is called

Sergio039 [100]

<span>The chemical mixture that composes our atmosphere is called Synopt.</span>

3 0

4 years ago

Now that you have exercised, walked your

ASHA 777 [7]

Answer: The moles of melatonin are 0.000043

Explanation:

According to avogadro's law, 1 mole of every substance weighs equal to its molecular mass and contains avogadro's number $6.023\times 10^{23}$ of particles.

To calculate the moles, we use the equation:

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

Given mass of melatonin = 0.01 g

Molar mass of melatonin $(C_{13}H_{16}N_2O_2)$ = 232.28 g/mol

$\text{Number of moles of melatonin}=\frac{0.01 g}{232.28g/mol}=0.000043mol$

Thus the moles of melatonin in 0.01 g are 0.000043

4 0

3 years ago