How many valence electrons does a neutral atom of silicon have??

How much water, in grams, can be made from 1.03 x <img src="https://tex.z-dn.net/?f=10%5E%7B24%7D" id="TexFormula1" title="10^{2

krok68 [10]

Answer:

30.8 g of water are produced

Explanation:

First of all we need the equation for the production of water:

2H₂ + O₂ → 2H₂O

2 moles of hydrogen react with 1 mol of oxygen in order to produce 2 moles of water.

As we assume, the oxygen in excess, we determine the moles of H₂.

1.03ₓ10²⁴ molecules . 1 mol/ 6.02ₓ10²³ molecules = 1.71 moles

Ratio is 2:2, so 1.71 moles will produce 1.71 moles of water

Let's convert the moles to mass: 1.71 mol . 18g / 1mol = 30.8 g of water are produced

5 0

4 years ago

If you wanted to protect water from freezing, which of the compounds below would accomplish this best. NaNO3, Mg(NO3)2, or Al(NO

Korvikt [17]

All of them are soluble salt.

First one dissociates into two ions.

The second one dissociates into 3 ions.

The third dissociate into 4 ions. therefore, Al(NO3)3

4 0

3 years ago

The following thermochemical equation is for the reaction of nitrogen(g) with oxygen(g) to form nitrogen dioxide(g). N2(g) + 2O2

Rzqust [24]

Answer: The mass of nitrogen gas reacted to produce given amount of energy is 5.99 grams.

Explanation:

The given chemical reaction follows:

$N_2(g)+2O_2(g)\rightarrow 2NO_2(g);\Delta H=66.4kJ$

We know that:

Molar mass of nitrogen gas = 28 g/mol

We are given:

Enthalpy change of the reaction = 14.2 kJ

To calculate the mass of nitrogen gas reacted, we use unitary method:

When enthalpy change of the reaction is 66.4 kJ, the mass of nitrogen gas reacted is 28 grams.

So, when enthalpy change of the reaction is 14.2 kJ, the mass of nitrogen gas reacted will be = $\frac{28}{66.4}\times 14.2=5.99g$

Hence, the mass of nitrogen gas reacted to produce given amount of energy is 5.99 grams.

8 0

4 years ago

When nitrogen dioxide (NO2) from car exhaust combines with water in the air, it forms nitric acid (HNO3), which causes acid rain

yKpoI14uk [10]

Answer:

For a: The number of molecules of nitrogen dioxide is $4.52\times 10^{23}$

For b: The mass of nitric acid formed is 54.81 grams

For c: The mass of nitric acid formed is 206 grams

Explanation:

The given chemical reaction follows:

$3NO_2(g)+H_2O(l)\rightarrow 2HNO_3(aq.)+NO(g)$

For a:

By Stoichiometry of the reaction:

1 mole of water reacts with 3 moles of nitrogen dioxide

So, 0.250 moles of water will react with $\frac{3}{1}\times 0.250=0.75mol$ of nitrogen dioxide

According to mole concept:

1 mole of a compound contains $6.022\times 10^{23}$ number of molecules.

So, 0.75 moles of nitrogen dioxide will contain $0.75\times 6.022\times 10^{23}=4.52\times 10^{23}$ number of molecules

Hence, the number of molecules of nitrogen dioxide is $4.52\times 10^{23}$

For b:

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

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

Given mass of nitrogen dioxide = 60.0 g

Molar mass of nitrogen dioxide = 46 g/mol

Putting values in equation 1, we get:

$\text{Moles of nitrogen dioxide}=\frac{60.0g}{46g/mol}=1.304mol$

By Stoichiometry of the reaction:

3 moles of nitrogen dioxide produces 2 mole of nitric acid

So, 1.304 moles of nitrogen dioxide will produce = $\frac{2}{3}\times 1.304=0.870$ moles of nitric acid

Now, calculating the mass of nitric acid from equation 1, we get:

Molar mass of nitric acid = 63 g/mol

Moles of nitric acid = 0.870 moles

Putting values in equation 1, we get:

$0.870mol=\frac{\text{Mass of nitric acid}}{63g/mol}\\\\\text{Mass of nitric acid}=(0.870mol\times 63g/mol)=54.81g$

Hence, the mass of nitric acid formed is 54.81 grams

For c:

For nitrogen dioxide:

Given mass of nitrogen dioxide = 225 g

Molar mass of nitrogen dioxide = 46 g/mol

Putting values in equation 1, we get:

$\text{Moles of nitrogen dioxide}=\frac{225g}{46g/mol}=4.90mol$

For water:

Given mass of water = 55.2 g

Molar mass of water = 18 g/mol

Putting values in equation 1, we get:

$\text{Moles of water}=\frac{55.2g}{18g/mol}=3.06mol$

By Stoichiometry of the reaction:

3 moles of nitrogen dioxide reacts with 1 mole of water

So, 4.90 moles of nitrogen dioxide will react with = $\frac{1}{3}\times 4.90=1.63mol$ of water

As, given amount of water is more than the required amount. So, it is considered as an excess reagent.

Thus, nitrogen dioxide is considered as a limiting reagent because it limits the formation of product.

By Stoichiometry of the reaction:

3 mole of nitrogen dioxide produces 2 moles of nitric acid

So, 4.90 moles of nitrogen dioxide will produce $\frac{2}{3}\times 4.90=3.27mol$ of nitric acid

Now, calculating the mass of nitric acid from equation 1, we get:

Molar mass of nitric acid = 63 g/mol

Moles of nitric acid = 3.27 moles

Putting values in equation 1, we get:

$3.27mol=\frac{\text{Mass of nitric acid}}{63g/mol}\\\\\text{Mass of nitric acid}=(3.27mol\times 63g/mol)=206g$

Hence, the mass of nitric acid formed is 206 grams

7 0

3 years ago

2) Nitrogen gas will react with hydrogen gas to produce ammonia, NH3, How many

Delicious77 [7]

Answer:

12 grams of hydrogen gas

and 56 grams of nitrogen gas

The molar mass of ammonia is 17 g/mol.

68 grams of ammonia corresponds to

17g/mol

68g

=4moles

4 moles of ammonia will be obtained from

2

4×1

=2 moles of nitrogen and

2

4×3

=6 moles of hydrogen.

The molar masses of nitrogen and hydrogen are 28 g/mol and 2 g/mol respectively.

2 moles of nitrogen corresponds to 2×28=56 grams.

6 moles of hydrogen corresponds to 6×2=12 grams.

5 0

2 years ago