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2 years ago

A flexible container at an initial volume of 5.120 L contains 8.500 mol of gas.

Chemistry

1 answer:

SOVA2 [1]2 years ago

6 0

Answer:

30.05 mol

Explanation:

solving the proportion

V1 / n1 = V2 / n2

5.120 L 18.10 L

–––––––– = ––––––

8.500 mol x

x = 30.05 mol

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What is △n for the following equation in relating Kc to Kp?

Nimfa-mama [501]

Answer:

-1

Explanation:

The relation between Kp and Kc is given below:

$K_p= K_c\times (RT)^{\Delta n}$

Where,

Kp is the pressure equilibrium constant

Kc is the molar equilibrium constant

R is gas constant , 0.082057 L atm.mol⁻¹K⁻¹

T is the temperature in Kelvins

Δn = (No. of moles of gaseous products)-(No. of moles of gaseous reactants)

For the first equilibrium reaction:

$2Na_{(s)}+2H_2O_{(l)}\rightleftharpoons 2NaOH_{(aq)}+2H_2_{(g)}$

<u>Δn = (No. of moles of gaseous products)-(No. of moles of gaseous reactants) = (2+1)-(2+2) = -1 </u>

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3 years ago

A large cyclotron directs a beam of He++ nuclei onto a target with a beam current of 0.250 mA. (a) How many He++ nuclei per seco

nikitadnepr [17]

Answer:

a. 7.8*10¹⁴ He⁺⁺ nuclei/s

b. 4000s

c. 7.7*10⁸s

Explanation:

I = 0.250mA = 2.5 * 10⁻³A

Q = 1.0C

1 e- contains 1.60 * 10⁻¹⁹C

But He⁺⁺ Carrie's 2 charge = 2 * 1.60*10⁻¹⁹C = 3.20*10⁻¹⁹C

(A).

No. Of charge per second = current passing through / charge

1 He⁺⁺ = 2.50 * 10⁻⁴ / 3.2*10⁻¹⁹C

1 He⁺⁺ = 7.8 * 10¹⁴ He⁺⁺ nuclei

(B).

I = Q / t

From this equation, we can determine the time it takes to transfer 1.0C

I = 1.0 / 2.5*10⁻⁴ = 4000s

(C).

Time it takes for 1 mol of He⁺⁺ to strike the target =?

Using Avogadro's ratio,

1.0 mole of He = (6.02 * 10²³ ions/mol ) * (1 / 7.81*10¹⁴ He ions)

Note : ions cancel out leaving the value of the answer in mols.

1.0 mol of He = 7.7 * 10⁸s

8 0

3 years ago

What is the formula for Silver (I) chloride?

Kisachek [45]

The formula for Silver (I) chloride is: AgCl

6 0

3 years ago

Read 2 more answers

In the following overall chemical reaction, aluminum displaces chromium from chromium(III) oxide and forms aluminum oxide.

mafiozo [28]

Answer:

Change in enthalpy for the reaction is -536 kJ

Explanation:

Overall chemical reaction can be represented a summation of two given elementary steps with slight modification.
Take reaction (1a) and divide stoichiometric coefficients by 2
Take reverse reaction (2a) and divide stoichiometric coefficient by 2
Then add these two modified elementary steps to get overall chemical reaction
$\Delta H$ is an additive property. hence value of $\Delta H$ will be changed in accordance with modification

$2Al+\frac{3}{2}O_{2}\rightarrow Al_{2}O_{3}.....\Delta H_{1}=\frac{-3351.4}{2}kJ=-1675.7kJ$

$Cr_{2}O_{3}\rightarrow 2Cr+\frac{3}{2}O_{2}....\Delta H_{2}=\frac{2279.4}{2}kJ=1139.7kJ$

--------------------------------------------------------------------------------------------------------------

$2Al+Cr_{2}O_{3}\rightarrow 2Cr+Al_{2}O_{3}....\Delta H=\Delta H_{1}+\Delta H_{2}=-1675.7+1139.7kJ=-536kJ$

6 0

3 years ago

28) Consider a 21.0 mL sample of pure lemon juice with a citric acid (H3C6H5O7) concentration of 0.30M. a. How many moles of cir

Damm [24]

<h3>#a. Answer:</h3>

0.0063 mole

<h3>Solution and explanation:</h3>

We are given 21.0 mL citric acid with a concentration of 0.30 M

Part a requires we calculate the number of moles of citric acid.

We need to know how to calculate the concentration of a solution;

Concentration or molarity = Number of moles ÷ Volume of the solution

Thus;

Number of moles = Concentration × Volume

Hence;

Moles = 0.30 M × 0.021 L

= 0.0063 mole

<h3>#b. Answer</h3>

1.21 g citric acid

<h3>Solution</h3>

Part B

We are required to calculate the mass of citric acid in the sample

Number of moles of a compound is calculated by dividing its mass by its molar mass.

Molar mass of Citric acid = 192.124 g/mol

Moles of citric acid = 0.0063 mole

But; Mass = Number of moles × Molar mass

Mass of citric acid = 0.0063 mol × 192.124 g/mol

= 1.21 g citric acid

<h3>#c. Answer</h3>

4.167 mL

<h3>Solution:</h3>

Part C

We are required to determine the initial volume before dilution;

We have;

Initial concentration (M1) = 0.30 M

Final volume (V2) = 250 mL or 0.25 L

Final concentration (M2) = 0.0050 M

Using the dilution formula we can get the initial volume;

Therefore, since; M1V1 =M2V2

V1 = M2V2÷M1

= (0.0050 × 0.25)÷ 0.30

= 0.004167 L or

= 4.167 mL

Therefore, the initial volume of the solution is 4.167 mL

8 0

3 years ago