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3 years ago

In past scientist used stars and planets to determine time?

Chemistry

1 answer:

Lynna [10]3 years ago

5 0

Answer:

Explanation:

they used stars and planets to orientate

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For the following reaction, calculate how many moles of each product are formed when 4.05 g of water is used.

timurjin [86]

Answer:

A. 0.225 mole of H₂

B. 0.113 mole of O₂.

Explanation:

We'll begin by calculating the number of mole in 4.05 g of water (H₂O). This can be obtained as follow:

Mass of H₂O = 4.05 g

Molar mass of H₂O = (2×1) + 16 = 2 + 16 = 18 g/mol

Mole of H₂O =?

Mole = mass /Molar mass

Mole of H₂O = 4.05 / 18

Mole of H₂O = 0.225 mole

Next, the balanced equation.

2H₂O —> 2H₂ + O₂

From the balanced equation above,

2 moles of H₂O produced 2 moles of H₂ and 1 mole of O₂.

A. Determination of the number of mole hydrogen produced.

From the balanced equation above,

2 moles of H₂O produced 2 moles of H₂.

Therefore, 0.225 mole of H₂O will also produce 0.225 mole of H₂.

B. Determination of the number of mole oxygen produced.

From the balanced equation above,

2 moles of H₂O produced 1 mole of O₂.

Therefore, 0.225 mole of H₂O will produce = (0.225 × 1)/2 = 0.113 mole of O₂.

Thus, 0.113 mole of O₂ is produced.

7 0

3 years ago

What happens to the energy absorbed during an endothermic reaction

LuckyWell [14K]

Answer:

more energy is absorbed when the bonds in the reactants are broken

4 0

2 years ago

What is the name of the compound Sr3N2?

nadezda [96]

The answer is Strontium Nitride

5 0

3 years ago

How can you described the energy of a storm

lakkis [162]

Answer:

When the surface water is warm, the storm sucks up heat energy from the water, just like a straw sucks up a liquid. This creates moisture in the air. If wind conditions are right, the storm becomes a hurricane. This heat energy is the fuel for the storm.

Explanation:

I hope this can help you!

4 0

3 years ago

How many grams of aluminum are required to react with 35 mL of 2.0 M hydrochloric acid, HCl?__ HCl + __ Al --> __ AlCl3 + __

kiruha [24]

Answer:

0.6258 g

Explanation:

To determine the number grams of aluminum in the above reaction;

determine the number of moles of HCl
determine the mole ratio,
use the mole ratio to calculate the number of moles of aluminum.
use RFM of Aluminum to determine the grams required.

Moles of HCl

35 mL of 2.0 M HCl

2 moles of HCl is contained in 1000 mL

x moles of HCl is contained in 35 mL

$x \: mol \: = \: \frac{2 \: \times \: 35}{1000} \\ = 0.07 \: moles \:$

We have 0.07 moles of HCl.

Mole ratio

Balanced equation

6HCl(aq) + 2Al(s) --> 2AlCl3(aq) + 3H2(g)

Hence mole ratio = 6 : 2 (HCl : Al

but moles of HCl is 0.07, therefore the moles of Al;

$= \frac{2}{6} \times 0.07 \\ \: = 0.0233333 \: moles$

Therefore we have 0.0233333 moles of aluminum.

Grams of Aluminum

We use the formula;

$grams \: = moles \: \times \: rfm$

The RFM (Relative formula mass) of aluminum is 26.982g/mol.

Substitute values into the formula;

$= 0.0233333 \: moles \: \times \: 26.982 \: \frac{g}{mol} \\ = 0.625799 \: grams$

The number of grams of aluminum required to react with HCl is 0.6258 g.

3 0

2 years ago