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iren2701 [21]
2 years ago
11

When the concentration of A in the reaction A ..... B was changed from 1.20 M to 0.60 M, the half-life increased from 2.0 min to

4.0 min at 25°C. Calculate the order of the reaction and the rate constant.
Chemistry
1 answer:
Reika [66]2 years ago
3 0

Answer:

2

0.4167\ \text{M}^{-1}\text{min}^{-1}

Explanation:

Half-life

{t_{1/2}}A=2\ \text{min}

{t_{1/2}}B=4\ \text{min}

Concentration

{[A]_0}_A=1.2\ \text{M}

{[A]_0}_B=0.6\ \text{M}

We have the relation

t_{1/2}\propto \dfrac{1}{[A]_0^{n-1}}

So

\dfrac{{t_{1/2}}_A}{{t_{1/2}}_B}=\left(\dfrac{{[A]_0}_B}{{[A]_0}_A}\right)^{n-1}\\\Rightarrow \dfrac{2}{4}=\left(\dfrac{0.6}{1.2}\right)^{n-1}\\\Rightarrow \dfrac{1}{2}=\left(\dfrac{1}{2}\right)^{n-1}

Comparing the exponents we get

1=n-1\\\Rightarrow n=2

The order of the reaction is 2.

t_{1/2}=\dfrac{1}{k[A]_0^{n-1}}\\\Rightarrow k=\dfrac{1}{t_{1/2}[A]_0^{n-1}}\\\Rightarrow k=\dfrac{1}{2\times 1.2^{2-1}}\\\Rightarrow k=0.4167\ \text{M}^{-1}\text{min}^{-1}

The rate constant is 0.4167\ \text{M}^{-1}\text{min}^{-1}

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15.50 g of NH4Cl reacts with an excess of AgNO3. In the reaction 35.50 g AgCl is produced. what is the theoretical yield of AgCl
Readme [11.4K]

Answer:

The answer to your question is 41.6 g of AgCl

Explanation:

Data

mass of NH₄Cl = 15.5 g

mass of AgNO₃ = excess

mass of AgCl = 35.5 g

theoretical yield = ?

Process

1.- Write the balanced chemical reaction.

              NH₄Cl  +  AgNO₃   ⇒   AgCl  +  NH₄NO₃

2.- Calculate the molar mass of NH₄Cl and AgCl

NH₄Cl = 14 + 4 + 35.5 = 53.5 g

AgCl = 108 + 35.5 = 143.5 g

3.- Calculate the theoretical yield

                 53.5 g of NH₄Cl -------------------- 143.5 g of AgCl

                  15.5 g of NH₄Cl  -------------------    x

                         x = (15.5 x 143.5) / 53.5

                         x = 2224.25 / 53.5

                         x = 41.6 g of AgCl

8 0
3 years ago
Which of the following molecules has one lone pair of electrons?
BigorU [14]
You can automatically rule out CH₄ since it has no lone pairs at all around the central atom. Water has 2. Ammonia is the only Lewis structure that contains one lone pair.
7 0
2 years ago
Read 2 more answers
The The thermal conductivity of a sheet of rigid, extruded insulation is reported to be k=0.029 W/ m measured temperature differ
vfiekz [6]

Answer:

Heat flux = 13.92 W/m2

Rate of heat transfer throug the 3m x 3m sheet = 125.28 W

The thermal resistance of the 3x3m sheet is 0.0958 K/W

Explanation:

The rate of heat transfer through a 3m x 3m sheet of insulation can be calculated as:

q=-k*A*\frac{\Delta T}{\Delta X}\\\\q=-0.029\frac{W}{m*K}*(3m*3m)*\frac{12K}{0.025m}  =125.28W

The heat flux can be defined as the amount of heat flow by unit of area.

Using the previous calculation, we can estimate the heat flux:

heat \, flux=\frac{q}{A}=\frac{125.28 W}{9 m^{2} }  =13.92 W/m^{2}

It can also be calculated as:

q/A=-k*\frac{\Delta T}{\Delta X}

The thermal resistance can be expressed as

\Delta T=R_t*Q\\R_t=\Delta T/Q=\frac{\Delta X}{k*A}

For the 3m x 3m sheet, the thermal resistance is

R_t = \frac{\Delta X}{k*A}=\frac{0.025m}{0.029W/mK*9m^{2}}=0.0958 \, K/W

4 0
3 years ago
The freezing point of a substance is -20°C. Its boiling point is 120°C.
Tasya [4]

Answer:

a. liquid

b. solid

c. gas, (should be at it's boiling point)

Explanation: If the normal melting point of a substance is below room temperature, the substance is a liquid at room temperature. Benzene melts at 6°C and boils at 80°C; it is a liquid at room temperature. If both the normal melting point and the normal boiling point are above room temperature, the substance is a solid.

if you need an explanation to each lmk

8 0
3 years ago
Solve the following mole-mass problem. Refer to the periodic table. How much mass does 0.50 mole of copper contain?
andre [41]
It is 31.75g of copper is contained in .50 mole of copper.
7 0
3 years ago
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