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4 years ago

What is the correct formula for calcium sulfate dihydrate?

Chemistry

1 answer:

Murljashka [212]4 years ago

3 0

Answer:

It is CaSO4.2H2O

Explanation:

Calcium has a valence of 2 because it has only two valency electrons.

Sulphate ( SO4)^2- is a radical with a valence value of 2.

When Calcium combines with sulphate in bonding,

Formular ==>  Ca2(SO4)2

But the 2 cancel out.

Overall formular==> CaSO4

For hydrated, ==> CaSO4.H2O

You might be interested in

What is the percentage of magnesium sulfate in MgSO4 x 7H2O.

son4ous [18]

48.78%
Percentage of MgSO4 = mass of MgSO4/ mass of sample (MgSO4. 7H20) and multiply it by 100.

5 0

4 years ago

Calculate the molarity of a 10.0% (by mass) aqueous solution of hydrochloric acid.

olga2289 [7]

The question is incomplete,the complete question :

Calculate the molality of a 10.0% (by mass) aqueous solution of hydrochloric acid:

a) 0.274 m

b) 2.74 m

c) 3.05 m

d) 4.33 m

e) the density of the solution is needed to solve the problem

Answer:

The molality of a 10.0% (by mass) aqueous solution of hydrochloric acid is 3.05 mol/kg.

Explanation:

10.0% (by mass) aqueous solution of hydrochloric acid.

10 grams of HCl is present in 100 g of solution.

Mass of HCl = 10 g

Mass of solution = 100 g

Mass of solution = Mass of solute + Mass of water

Mass of water = 100 g - 10 g = 90 g

Moles of HCl = $\frac{10 g}{36.5 g/mol}=0.2740 mol$

Mass of water in kilograms = 0.090 kg

Molality = $\frac{0.2740 mol}{0.090 kg}=3.05 mol/kg$

The molality of a 10.0% (by mass) aqueous solution of hydrochloric acid is 3.05 mol/kg.

6 0

3 years ago

b) If 1.5 mole of oxygen reacted, how many mole of iron (III) oxide would be formed from the reaction?

lyudmila [28]

Answer:

If there reacted 1.5 moles of O2, there will be produced 1.0 mol of Fe2O3

Explanation:

Step 1: Data given

Number of moles oxygen reacted = 1.5 moles

Step 2: The balanced equation

4Fe + 3O2 → 2Fe2O3

Step 3: Calculate moles of Fe2O3

For 4 moles Fe consumed, we need 3 moles of O2 to produce 2 moles of Fe2O3

For 1.5 moles O2 consumed, we'll have 2/3 * 1.5 = 1.0 mol of Fe2O3

If there reacted 1.5 moles of O2, there will be produced 1.0 mol of Fe2O3

7 0

3 years ago

A gas that exerts a pressure of 537 torr in a container with a volume of 5.30 L will exert a pressure of 255 torr when transferr

ArbitrLikvidat [17]

Answer:- The gas needs to be transferred to a container with a volume of 11.2 L.

Solution:- From Boyle's law. "At constant temperature, Volume is inversely proportional to the pressure."

It means, the volume is decreased if the pressure is increased and vice versa.

Here, the Pressure is decreasing from 537 torr to 255 torr. So, the volume must increase and calculated by using the equation:

$P_1V_1=P_2V_2$

Where, $P_1$ is initial pressure and $P_2$ is final pressure. Similarly, $V_1$ is initial volume and $V_2$ is final volume.

Let's plug in the values in the equation:

(537 torr)(5.30 L) = (255 torr)( $V_2$ )

$V_2=(\frac{537 torr*5.30 L}{255 torr})$

$V_2$ = 11.2 L

So, the new volume of the container needs to be 11.2 L.

4 0

3 years ago

Correct way for calculating atomic mass

kolezko [41]

Answer:

mass number = protons + neutrons.

Explanation:

Together, the number of protons and the number of neutrons determine an element's mass number: mass number = protons + neutrons. If you want to calculate how many neutrons an atom has, you can simply subtract the number of protons, or atomic number, from the mass number.

5 0

2 years ago