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3 years ago

Plz help chemistry test I’ll mark brainliest !

Chemistry

2 answers:

777dan777 [17]3 years ago

8 0

C - the expanded use of fossil fuels

rjkz [21]3 years ago

3 0

Answer:

expanded use of fossil fuels

Explanation:

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Consider the reaction Mg₂Si(s) + 4 H₂O(ℓ) → 2 Mg(OH)₂(aq) + SiH₄(g). How many grams of silane gas (SiH₄) are formed if 25.0 g of

Neko [114]

Answer:

10.60 grams of silane gas are formed.

Explanation:

From the reaction:

Mg₂Si(s) + 4H₂O(l) → 2Mg(OH)₂(aq) + SiH₄(g)

We know that the limiting reactant is Mg₂Si, so to find the mass of SiH₄ formed we need to calculate the number of moles of Mg₂Si:

$\eta_{Mg_{2}Si} = \frac{m_{Mg_{2}Si}}{M_{Mg_{2}Si}}$

Where:

m: is the mass of Mg₂Si = 25.0 g

M: is the molar mass of Mg₂Si = 76.69 g/mol

$\eta_{Mg_{2}Si} = \frac{m_{Mg_{2}Si}}{M_{Mg_{2}Si}} = \frac{25.0 g}{76.69 g/mol} = 0.33 moles$

Now, the stoichiometric relation between Mg₂Si and SiH₄ is 1:1 so:

$\eta_{Mg_{2}Si} = \eta_{SiH_{4}} = 0.33 moles$

Finally, the mass of SiH₄ is:

$m_{SiH_{4}} = \eta_{SiH_{4}}*M_{SiH_{4}} = 0.33 moles*32.12 g/mol = 10.60 g$

Therefore, 10.60 grams of silane gas are formed.

I hope it helps you!

3 0

3 years ago

During a chemical change items are lost or gained to make new substance true or false

Otrada [13]

Answer:

If you meant Atoms then the answer is false

5 0

3 years ago

Please help me I don’t know this

Zina [86]

Answer:

aplha particle is the answer

5 0

3 years ago

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

4 years ago

Read 2 more answers

What is the electron configuration of an element with atomic number 20?

Vedmedyk [2.9K]

[Ar]4s^2
hope it helps

8 0

3 years ago

Read 2 more answers