All categories

3 years ago

Which statement is true for all minerals?

Chemistry

2 answers:

astraxan [27]3 years ago

7 0

D
C.
They are made of silicon and oxygen

ss7ja [257]3 years ago

5 0

A. because atoms create crystal structures to form different kind of materials

You might be interested in

How many tons of zinc can be obtained from 976 tons of zinc ore that is 78.0% zinc carbonate?

kramer

First, calculating the amount of zinc carbonate by multiplying the given mass of the ore by the percent zinc carbonate.
mass of zinc carbonate = (976 tons)(0.78)
= 761.28 tons
Then, calculate for %Zn in zinc carbonate
%Zn = ((65.38) / (125.39)) x 100%
% Zn = 52.141%
tons of Zn from the sample,
mass of Zn = (761.28 tons)(0.52141)
= 396.94 tons Zn

6 0

3 years ago

Read 2 more answers

How many neutrons are in a Cs-130 isotope?

den301095 [7]

It has 78 neutrons in a cesium

5 0

3 years ago

Which of the following is considered an ignition source?

matrenka [14]

A.

Weldings sparks could start fire on wood.

Lightning can ignite a fire one a tall tree

Open flames can start another fire if made in contact especially with flammable substances

4 0

3 years ago

Fe2O3 + CO → Fe + CO2 If 2 moles of Fe2O3 react with 9 moles of CO, how many moles of each product are formed?

Y_Kistochka [10]

Answer: B. 4 moles Fe and 3 moles CO2

Explanation:

write a balanced chemical reaction

that is FeO3 + 3 CO → 2 Fe + 3CO2

2 moles of Fe2O3 reacted with 3 x2=6 moles of Co to form Fe and CO2 therefore CO was in excess and Fe2O3 was limiting reagent.

use the mole ratio to determine the moles of each product.

that is the mole ratio 0f Fe2O3 : Fe is 1:2 therefore the moles of Fe = 2x2=4 moles

the mole ratio of Fe2CO3 : CO2 is 1: 3 therefore the moles of Co2 = 2 x3 = 6 moles

8 0

2 years ago

Read 2 more answers

Hydrogen fluoride is used in the manufacture of Freons (which destroy ozone in the stratosphere) and in the production of alumin

Lerok [7]

Answer: The percentage yield of HF is 73.36 %

Explanation:

To calculate the number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$ ....(1)

For calcium fluoride:

Given mass of calcium fluoride = 6.25 kg = 6250 g (Conversion factor: 1 kg = 1000 g)

Molar mass of calcium fluoride = 78.07 g/mol

Putting values in above equation, we get:

$\text{Moles of calcium fluoride}=\frac{6250g}{78.07g/mol}=80.05mol$

For the given chemical reaction:

$CaF_2+H_2SO_4\rightarrow CaSO_4+2HF$

By Stoichiometry of the reaction:

1 mole of calcium fluoride produces 2 moles of hydrofluoric acid

So, 80.05 moles of calcium fluoride will produce = $\frac{2}{1}\times 80.05=160.1mol$ of hydrofluoric acid

Now, calculating the theoretical yield of hydrofluoric acid using equation 1, we get:

Moles of of hydrofluoric acid = 160.1 moles

Molar mass of hydrofluoric acid = 20.01 g/mol

Putting values in equation 1, we get:

$160.1mol=\frac{\text{Theoretical yield of hydrofluoric acid}}{20.01g/mol}=3203.6g=3.20kg$

To calculate the percentage yield of hydrofluoric acid, we use the equation:

$\%\text{ yield}=\frac{\text{Experimental yield}}{\text{Theoretical yield}}\times 100$

Experimental yield of hydrofluoric acid = 2.35 kg

Theoretical yield of hydrofluoric acid = 3.20 kg

Putting values in above equation, we get:

$\%\text{ yield of hydrofluoric acid}=\frac{2.35g}{3.20g}\times 100\\\\\% \text{yield of hydrofluoric acid}=73.36\%$

Hence, the percentage yield of HF is 73.36 %

4 0

3 years ago