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3 years ago

What is the molarity of 50.84 g of Na2CO3 dissolved in 0.400 L solution?

Chemistry

1 answer:

borishaifa [10]3 years ago

4 0

Answer:

1.20 M

Explanation:

Convert grams of Na₂CO₃ to moles. (50.84 g)/(105.99 g/mol) = 0.4797 mol

Molarity is (moles of solute)/(liters of solvent) = (0.4797 mol)/(0.400 L) = 1.20 M

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If the sample contained 2.0 moles of KClO3 at a temperature of 214.0 °C, determine the mass of the oxygen gas produced in grams

Westkost [7]

Answer : The mass of the oxygen gas produced in grams and the pressure exerted by the gas against the container walls is, 96 grams and 1.78 atm respectively.

Explanation : Given,

Moles of $KCl_3$ = 2.0 moles

Molar mass of $O_2$ = 32 g/mole

Now we have to calculate the moles of $MgO$

The balanced chemical reaction is,

$2KClO_3\rightarrow 2KCl+3O_2$

From the balanced reaction we conclude that

As, 2 mole of $KClO_3$ react to give 3 mole of $O_2$

So, 2.0 moles of $KClO_3$ react to give $\frac{2.0}{2}\times 3=3.0$ moles of $O_2$

Now we have to calculate the mass of $O_2$

$\text{ Mass of }O_2=\text{ Moles of }O_2\times \text{ Molar mass of }O_2$

$\text{ Mass of }O_2=(3.0moles)\times (32g/mole)=96g$

Therefore, the mass of oxygen gas produced is, 96 grams.

Now we have to determine the pressure exerted by the gas against the container walls.

Using ideal gas equation:

$PV=nRT\\\\PV=\frac{w}{M}RT\\\\P=\frac{w}{V}\times \frac{RT}{M}\\\\P=\rho\times \frac{RT}{M}$

where,

P = pressure of oxygen gas = ?

V = volume of oxygen gas

T = temperature of oxygen gas = $214.0^oC=273+214.0=487K$

R = gas constant = 0.0821 L.atm/mole.K

w = mass of oxygen gas

$\rho$ = density of oxygen gas = 1.429 g/L

M = molar mass of oxygen gas = 32 g/mole

Now put all the given values in the ideal gas equation, we get:

$P=1.429g/L\times \frac{(0.0821L.atm/mole.K)\times (487K)}{32g/mol}$

$P=1.78atm$

Thus, the pressure exerted by the gas against the container walls is, 1.78 atm.

7 0

3 years ago

What is the value of the equilibrium constant at 25 oC for the reaction between the pair: Br2(l) and I-(aq) Use the reduction po

Vikki [24]

Answer:

1.58×10E18

Explanation:

Since we have the reduction potentials we could make decisions regarding which one will be the anode or cathode. Evidently, bromine having the more positive reduction potential will be the cathode while the iodine will be the anode.

E°cell= 1.07- 0.53= 0.54 V

E°cell= 0.0592/n logK

0.54 = 0.0592/2 logK

logK= 0.54/0.0296

logK= 18.2

K= Antilog (18.2)

K= 1.58×10^18

3 0

3 years ago

Vitamin C contains the elements C, H, and O. It is known to contain 40.9% C and 4.58% H by mass. The molar mass of vitamin C has

soldier1979 [14.2K]

Answer:

C₆H₈O₆

Explanation:

First off, the percent of oxygen by mass of vitamin C is:

100 - (40.9+4.58) = 54.52 %

Assume we have one mol of vitamin C. Then we would have 180 grams, of which:

180 * 40.9/100 = 73.62 grams are of Carbon

180 * 4.58/100 = 8.224 grams are of Hydrogen

180 * 54.52/100 = 98.136 grams are of Oxygen

Now we convert each of those masses to moles, using the elements' respective atomic mass:

C ⇒ 73.62 g ÷ 12 g/mol = 6.135 mol C ≅ 6 mol C

H ⇒ 8.224 g ÷ 1 g/mol = 8.224 mol H ≅ 8 mol H

O ⇒ 98.136 g ÷ 16 g/mol = 6.134 mol O ≅ 6 mol O

So the molecular formula for vitamin C is C₆H₈O₆

8 0

3 years ago

Which power source uses the earth’s internal heat?

Nataly_w [17]

Answer:

Its geothermal energy.

Explanation:

hope this helps

5 0

3 years ago

How do you explain reaction of stiochiometry

Mama L [17]

Answer:

Chemical reactions are balanced by adding coefficients so that the number of atoms of each element is the same on both sides. Stoichiometry describes the relationship between the amounts of reactants and products in a reaction.

Explanation:

3 0

4 years ago