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3 years ago

How many grams are in 21.7 mol of H2O?

Chemistry

2 answers:

Fantom [35]3 years ago

5 0

Answer:

390.6 gram

Explanation:

Mass in gram = no of moles × molar mass

Mass in gram = 21.7×18

= 390.6 gram

Gnoma [55]3 years ago

4 0

Answer:

390.931576 grams

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I need help! how many moles are in 3.4*10^-7 grams of silicon dioxide, SiO2. I got 2.0^17 but I think it's wrong :(

blondinia [14]

Molar mass SiO2 = 28 + 32 = 60

so moles sand = 3.4 x 10-7 / 60

8 0

3 years ago

For the reactions system 2H2(g) + S2(g) 2H2S(g), a 1.00 liter vessel is found to contain 0.50 moles of H2, 0.020 moles of S2, an

Ne4ueva [31]

Answer:

K = 9.4 *10^5

The reaction favor product formation

Explanation:

Equilibrium constant of a chemical reaction is the value of its reaction quotient at chemical equilibrium. Also it is defined as the ratio of the product of concentration of products to the product of concentration of reactants each term raised to power equal their stochiometric coefficients.

so, for the reaction,

2H₂ ₍g₎ + S₂ ₍g₎ → 2H₂S ₍g₎

The equilibrium constant can be expressed as following:

$K_{eq}=\frac{[H_2S]^2}{H_2]^2\times [S_2]}$

where concentration of reactants and products is expressed in molarity Molarity=(no of moles/ Volume L)

So,

[H₂] = (0.50 mol / 1 L) = 0.50 M

[S₂] = (0.02 mol / 1 L) = 0.020 M

[H₂S] = (68.5 mol / 1 L) = 68.5 M

∴ K_{eq}=\frac{[68.5]^2}{0.50]^2\times [0.020]}=9.4*10^5

As the value of K is greater than 1, the reaction favor product formation.

4 0

3 years ago

Read 2 more answers

Distinguish between the terms "insoluble" and "unsaturated." Give an example to illustrate each term.

Serjik [45]

Insoluble means that a substance does not dissociate in another, like mixing water and oil.

In an unsaturated solution, the solute does dissociate into solution but there is more "room" in the solution to hold more. Say if you have an amount of water that can dissolve 20g of salt but you only have 15g dissolved in it, that solution is unsaturated.

4 0

4 years ago

a radioisotope has a half life of three hours how much of a 120g sample remains after 9 hours. what will the g amount be after 3

aksik [14]

$\huge\boxed{♔︎Answer♔︎}$

60g after 3 hours, 30g after 6 hours and 15g after 9 hours

Explanation:

Weight of the radioactive sample = 120g

half life time period = 3 hours

(a) The weight of sample after 3 hours

$\textsf{ No. of half lives} = \sf \cancel\frac{3}{3} = 1$

The fraction of sample left

$\sf { \frac{1}{2} }^{1} = \frac{1}{2}$

Mass of the sample left

$\sf \frac{1}{2} \times 120 = \cancel\frac{120}{2} = 60g$

60g of sample is left after 3 hours

(b) The weight of sample after 6 hours

$\textsf{ No. of half lives} = \sf \cancel\frac{6}{3} = 2$

The fraction of the sample left

$\sf { \frac{1}{2} }^{2} = \frac{1}{2} \times \frac{1}{2} = \frac{1}{4}$

Mass of the sample left

$\sf \frac{1}{4} \times 120 = \cancel\frac{120}{4} = 30g$

30g of sample is left after 6 hours

$\textsf {No. of half lives} = \sf \cancel\frac{9}{3} = 3$

The fraction of sample left

$\sf { \frac{1}{2} }^{3} = \frac{1}{2} \times \frac{1}{2} \times \frac{1}{2} = \frac{1}{8}$

Mass of sample left

$\sf \frac{1}{8} \times 120 = \cancel \frac{120}{8} = 15g$

15g of sample is left after 9 hours.

3 0

2 years ago

In which of the following does matter change into a new substance?

cestrela7 [59]

Answer:

Chemical change

Explanation:

Matter changes into a new substance by changing into a chemical change. In a chemical change, the substance cannot be changed back to its previous state and a new substance is formed.

4 0

3 years ago

Read 2 more answers