What is the wavelength of light emitted between the 3 rd and 1 st energy levels? 121.5 nm 94.5 nm 102.5 nm 1875 nm

A cylinder contains 3.1 L of oxygen at 300 K and 2.7 atm. The gas is heated, causing a piston in the cylinder to move outward. T

zubka84 [21]

Answer: The moles of gas present in the cylinder is 0.34 moles.

Explanation:

Given: $P_{1}$ = 2.7 atm, $V_{1}$ = 3.1 L, $T_{1}$ = 300 K

$P_{2}$ = ?, $V_{2}$ = 9.4 L, $T_{2}$ = 610 K

Formula used to calculate the final temperature is as follows.

$\frac{P_{1}V_{1}}{T_{1}} = \frac{P_{2}V_{2}}{T_{2}}$

Substitute the values into above formula as follows.

$\frac{P_{1}V_{1}}{T_{1}} = \frac{P_{2}V_{2}}{T_{2}}\\\frac{2.7 atm \times 3.1 L}{300 K} = \frac{P_{2} \times 9.4 L}{610 K}\\P_{2} = \frac{5105.7}{2820} atm\\= 1.81 atm$

Now, moles present upon heating the cylinder are as follows.

$P_{2}V_{2} = n_{2}RT_{2}\\1.81 atm \times 9.4 L = n_{2} \times 0.0821 L atm/mol K \times 610 K\\n_{2} = \frac{17.014}{50.081} mol\\= 0.34 mol$

Thus, we can conclude that moles of gas present in the cylinder is 0.34 moles.

6 0

3 years ago

An atom contains 6 protons what element is that

Degger [83]

6 protons would be Carbon, C

6 0

3 years ago

1) on combustion, 1 mole of an alkane gives 2 moles of carbon dioxide and 3 moles of water. Suggest the molecular formula of thi

Crazy boy [7]

1 mole of an alkane gives 2 moles is correct answer

6 0

3 years ago

How much<br>much hydrogen gas evolved<br>when 1.5 current is passed through water for 1.5 hours?

evablogger [386]

0.042 moles of Hydrogen evolved

<h3>Further explanation</h3>

Given

I = 1.5 A

t = 1.5 hr = 5400 s

Required

Number of Hydrogen evolved

Solution

Electrolysis of water ⇒ decomposition reaction of water into Oxygen and Hydrogen gas.

Cathode(reduction-negative pole) : 2H₂O(l)+2e⁻ ⇒ H₂(g)+2OH⁻(aq)

Anode(oxidation-positive pole) : 2H₂O(l)⇒O₂(g)+4H⁻(aq)+4e⁻

Total reaction : 2H₂O(l)⇒2H₂(g)+O₂(g)

So at the cathode H₂ gas is produced

Faraday : 1 mole of electrons (e⁻) contains a charge of 96,500 C

$\tt mol~e^-=\dfrac{Q}{96500}$

Q = i.t

Q = 1.5 x 5400

Q = 8100 C

mol e⁻ = 8100 : 96500 = 0.084

From equation at cathode , mol ratio e⁻ : H₂ = 2 : 1, so mol H₂ = 0.042

4 0

3 years ago

In the reaction fecl2 + 2naoh fe(oh)2(s) + 2nacl, if 6 moles of fecl2 are added to 6 moles of naoh, how many moles of fecl2 woul

pychu [463]

The balanced chemical reaction would be

<span>fecl2 + 2naoh = fe(oh)2(s) + 2nacl

Initial amounts of the reactants are given, so, we need to determine which of the reactants is the limiting reactant and use this amount to determine what is asked. However, what is being asked is how many of the FeCl2 is used in the reaction, showing that it is NaOH that is the limiting reactants. Thus, we just use the initial amount of NaOH and relate the substances by the chemical reaction as follows:

6 mol NaOH ( 1 mol FeCl2 / 2 mol NaOH ) = 3 mol FeCl2

Therefore, 3 moles of FeCl2 is used up and 3 moles of FeCl2 is also left after the reaction.</span>

5 0

3 years ago

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