Which is always true of a salt?

How many half-lives are required for the concentration of reactant to decrease to 1.56% of its original value?4247.56.56

neonofarm [45]

Answer:

6 half-lives are required for the concentration of reactant to decrease to 1.56% of its original value.

Explanation:

Using integrated rate law for first order kinetics as:

$[A_t]=[A_0]e^{-kt}$

Where,

$[A_t]$ is the concentration at time t

$[A_0]$ is the initial concentration

Given:

Concentration is decreased to 1.56 % which means that 0.0156 of $[A_0]$ is decomposed. So,

$\frac {[A_t]}{[A_0]}$ = 0.0156

Thus,

$\frac {[A_t]}{[A_0]}=e^{-k\times t}$

$0.0156=e^{-k\times t}$

kt = 4.1604

The expression for the half life is:-

Half life = 15.0 hours

$t_{1/2}=\frac {ln\ 2}{k}$

Where, k is rate constant

So,

$k=\frac {ln\ 2}{t_{1/2}}$

$\frac{4.1604}{t}=\frac {ln\ 2}{t_{1/2}}$

$t = 6\times t_{1/2}$

<u>6 half-lives are required for the concentration of reactant to decrease to 1.56% of its original value.</u>

6 0

3 years ago

The gaseous product of a reaction is collected in a 25.0L container at 27.0 C. The pressure in the container is 3.0atm and the g

NeX [460]

Answer: The molar mass of the gas is 31.6 g/mol

Explanation:

According to ideal gas equation:

$PV=nRT$

P = pressure of gas = 3.0 atm

V = Volume of gas = 25.0 L

n = number of moles = ?

R = gas constant = $0.0821Latm/Kmol$

T =temperature = $27.0^0C=(27.0+273)K=300K$

$n=\frac{PV}{RT}$

$n=\frac{3.0atm\times 25.0L}{0.0821 L atm/K mol\times 300K}=3.04moles$

Moles = $\frac{\text {given mass}}{\text {Molar mass}}$

$3.04=\frac{96.0g}{\text {Molar mass}}$

${\text {Molar mass}}=31.6g/mol$

The molar mass of the gas is 31.6 g/mol

4 0

2 years ago

What is the hydrogen ion concentration of a solution with a pH of 2.0?

aliina [53]

Answer:

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Explanation:

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8 0

3 years ago

URGENT!!! What is the balanced form of this equation?

Ostrovityanka [42]

Explanation: This is a reaction of oxidation of $H_2O_2$ in the presence of acidified $KMnO_4$ . Acidified $KMnO_4$ is a strong oxidizing agent.