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2 years ago

How many moles is in 175.5g of NaCl?

1 answer:

7 0

You need to find the formula mass of NaCl first, which you find the amu of both sodium and chlorine on the periodic table and you add them both. Then you divide the 175.5g by the formula mass which I got 58 g to get 3.026 moles of NaCl. 4 sig figs because of the 175.5. I recommend doing it on your own to make sure you get the right answer. You divide the 175.5g of NaCl by the formula mass.

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What is the volume of 15.2 grams of SO2 at STP?

kiruha [24]

5.512 litres is the volume of 15.2 grams of sulphur dioxide gas at STP.

Explanation:

Data given:

mass of sulphur dioxide = 15.2 grams

conditions is at STP whech means volume = 22.4 litres

atomic mass of sulphur dioxide = 64.06 grams/mole

Number of moles is calculated as:

number of moles = $\frac{mas}{atomic mass of 1 mole}$

Putting the values in the equation:

number of moles = $\frac{15.2}{64.06}$

= 0.23 moles

Assuming that sulphur dioxide behaves as an ideal gas, we can calculate the volume as:

When 1 mole of sulphur dioxide occupies 22.4 litres at STP

Then 0.23 moles of sulphur dioxide occupies 22.4 x 0.23

= 5.152 litres is the volume.

5 0

3 years ago

What is the change in internal energy (ΔΕ) of a system when 5 kJ of work is done on the system while it releases 13 kJ of energy

meriva

The change in internal energy (ΔΕ) of a system : -8 kJ

<h3>Further explanation </h3>

The laws of thermodynamics 1 state that: energy can be changed but cannot be destroyed or created

The equation is:

$\tt \Delta U=Q+W$

Energy owned by the system is expressed as internal energy (U)

This internal energy can change if it absorbs heat Q (U> 0), or releases heat (U <0). Or the internal energy can change if the system does work or accepts work (W)

The sign rules for heat and work are set as follows:

• The system receives heat, Q +

• The system releases heat, Q -

• The system does work, W -

• the system accepts work, W +

5 kJ of work is done on the system : W = +5 kJ

releases 13 kJ of energy to the surroundings : Q = -13 kJ

$\tt \Delta E=-13+5=-8~kJ$

6 0

2 years ago

Calculate the molar mass of CH4 gas at STP when 5.46Lof the gas weighs 4g??

meriva

Answer:

About 16.42 grams

Explanation:

$PV=nRT \\\\(1)(5.46L)=n(0.0821)(273) \\\\n\approx 0.2436 \\\\4g/0.2436\approx 16.42$

Hope this helps!

6 0

3 years ago

Why is gold considered matter?

Yakvenalex [24]

Answer:

All matter is made up of substances called elements, which have specific chemical and physical properties and can't be broken down into other substances through ordinary chemical reactions. Gold, in this case, is an element so, therefore, it is considered matter.

Hope it helped :)

3 0

3 years ago

Which of the following elements is commonly found in the Earth's crust, living matter, oceans, and atmosphere? hydrogen , neon g

Svetlanka [38]

Answer: hydrogen

Explanation: hydrogen gas is a major component of water which occupies a large portion of the Earth's atmosphere

4 0

3 years ago