25.4 g of salt was dissolved in distilled water to make 425 mL of solution.

A decomposition reaction has a half life of 578 years. (a) What is the rate constant for this reaction? (b) How many years does

maw [93]

Answer:

$0.001199 year^{-1}$ is the rate constant for this reaction.

It will take $1.73\times 10^3 years$ to concentration to reach 12.5% of its original value.

Explanation:

A decomposition reaction follows first order kinetics:

Half life of the reaction = $t_{1/2}=578 years$

Rate constant of the reaction = k

For first order reaction, half life and rate constant are linked with an expression :

$k=\frac{0.693}{t_{1/2}}$

$k=\frac{0.693}{578 years}=0.001199 year^{-1}$

$0.001199 year^{-1}$ is the rate constant for this reaction.

Initial concentration of reactant = $[A_o]$ = x

Final concentration of reactant after time t = $[A]$ = 12.5% of x = 0.125x

The integrated law of first order reaction :

$[A]=[A_o]\times e^{-kt}$

$0.125x=x\times e^{-0.001199 year^{-1}\times t}$

t = 1,734.31 years = $1.73\times 10^3 years$

It will take $1.73\times 10^3 years$ to concentration to reach 12.5% of its original value.

3 0

3 years ago

What is the meaning of uniformitarianism?

scZoUnD [109]

It's mean the theory that changes in the earth's crust during geological history have resulted from the action of continuous and uniform processes.

7 0

3 years ago

Which solution when mixed with a drop ofbromthymol blue will cause the indicator to change from blue to yellow

zheka24 [161]

Answer: A

Explanation: the only way to turn it from blue to yellow is to mix it with an acidic solution.

6 0

3 years ago

Read 2 more answers

A dehumidifier takes water vapor from the air by passing the moist air over a set of cold coils to perform a state change. How d

aksik [14]

A fan pulls in air from the surrounding area, which typically has high moisture levels.

When the air passed through the dehumidifier , it touches the cooling coils , which in turn pull moisture from the air by lowering temperature.

6 0

3 years ago

When a 5.00-g metal piece, A, was immersed in 38.0 mL of water, the water level rose to 50.0 mL. Similarly, when a 5.00-g metal

Mnenie [13.5K]

Answer:

A is denser than B as it's volume for the same mass is smaller.

Explanation:

Hello.

In this case, we first need to take into account that the density of each metal A and B is computed by dividing the mass over the volume of each metal which is actually computed by substracting the volume of water from the volume of the water and the solid:

$V_A=50.0mL-38.0mL=12.0mL\\\\V_B=60.0mL-38.0mL=22.0mL$

Next, we compute the densities as shown below:

$\rho_A=\frac{m_A}{V_A}=\frac{5.00g}{12.0mL}=0.42g/mL\\ \\\rho_B=\frac{m_B}{V_B}=\frac{5.00g}{22.0mL}=0.23g/mL$

In such a way, A is denser is B as it's volume for the same mass is smaller.

Best regards.

4 0

3 years ago