What is the total number of valence electrons in a sulfide in th ground state?

Formula for Sodium Hydrogen Carbonate NaHCO3? or Na2HCO3?

yan [13]

NaHCO3 is the right answer

8 0

3 years ago

A gas used to extinguish fires is composed of 75 % CO2 and 25 % N2. It is stored in a 5 m3 tank at 300 kPa and 25 °C. What is th

tatyana61 [14]

Answer : The partial pressure of the $CO_2$ in the tank in psia is, 32.6 psia.

Explanation :

As we are given 75 % $CO_2$ and 25 % $N_2$ in terms of volume.

First we have to calculate the moles of $CO_2$ and $N_2$ .

$\text{Moles of }CO_2=\frac{\text{Volume of }CO_2}{\text{Volume at STP}}=\frac{75}{22.4}=3.35mole$

$\text{Moles of }N_2=\frac{\text{Volume of }N_2}{\text{Volume at STP}}=\frac{25}{22.4}=1.12mole$

Now we have to calculate the mole fraction of $CO_2$ .

$\text{Mole fraction of }CO_2=\frac{\text{Moles of }CO_2}{\text{Moles of }CO_2+\text{Moles of }N_2}$

$\text{Mole fraction of }CO_2=\frac{3.35}{3.35+1.12}=0.75$

Now we have to calculate the partial pressure of the $CO_2$ gas.

$\text{Partial pressure of }CO_2=\text{Mole fraction of }CO_2\times \text{Total pressure of gas}$

$\text{Partial pressure of }CO_2=0.75mole\times 300Kpa=225Kpa=225Kpa\times \frac{0.145\text{ psia}}{1Kpa}=32.625\text{ psia}$

conversion used : (1 Kpa = 0.145 psia)

Therefore, the partial pressure of the $CO_2$ in the tank in psia is, 32.6 psia.

3 0

2 years ago

A silicon wafer with dimensions 15.00 cm x 15.00 cm x 0.0400 cm

Oxana [17]

The silicon wafer contains 20.96 g of silicon.

The mole of a substance is related to its mass and molar mass by the following equation:

<h3>Mole = mass / molar mass ....... (1)</h3>

Making mass the subject of the above equation, we have

<h3>Mass = mole × molar mass ..... (2)</h3>

With the above formula (i.e equation 2), we can obtain the mass of silicon in the wafer as follow:

Mole silicon = 0.746 mole

Molar mass of silicon = 28.09 g/mol

<h3>Mass of silicon =? </h3>

Mass = mole × molar mass

Mass = 0.746 × 28.09

<h3>Mass of silicon = 20.96 g</h3>

Therefore, the mass of silicon in the wafer is 20.96 g

Learn more: brainly.com/question/24639749

3 0

2 years ago

What is the mass of a sample of a sample of iron (cp=0.44j/g•°C) when it is heated from 60°to 160°C. The heat is transferred is

scZoUnD [109]

Q=mcat

6600=(m)(.44)(100)

6600=(44m)

150= m

5 0

3 years ago

Consider 100.0-g samples of two different compounds consisting only of carbon and oxygen. one compound contains 27.2 g of carbon

Sliva [168]

This is a tricky question. All that matters are ratios of percentages, not percentages themselves. So no one should directly compare 27.2 with 42.9. We must and shall compare the ratios (27.2 to 72.8) and (42.9 to 57.1).

Take them both down to 1 to and see what happens.

Working out the formulas knowing atomic masses is a bit beside the point; this is how people first DISCOVERED the idea of atomic mass.

A

Carbon Oxygen

27.2g 72.8g (100-27.2)

Moles 27.2/12 72.8/16

2.27 4.55

Ratio 1 2

Do the same with the other

4 0

3 years ago

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