All categories

3 years ago

What fraction of a sample of 6832ge, whose half-life is about 9 months, will remain after 2.9 yr ?

1 answer:

4 0

The half-life of 9 months is 0.75 years. 2.0 years is 2.0/0.75 = 2.67 half-lives. Each half-life represents a reduction in the amount remaining by a factor of two, so: A(t)/A(0) = 2^(-t/h) where A(t) = amount at time t h = half-life in some unit t = elapsed time in the same unit A(t)/A(0) = 2^(-2.67) = 0.157 15.7% of the original amount will remain after 2.0 years. This is pretty easy one to solve. I was happy doing it.

You might be interested in

Light bulbs transform electrical energy to light energy. No energy transformation is 100%. Thus, in the transfer from electrical

arlik [135]

Answer: a

Explanation: usa test prep said it was right

7 0

3 years ago

Read 2 more answers

A solution was prepared by dissolving 0.800 g of sulfur S8, in 100.0 g of acetic acid, HC2H3O2. Calculate the freezing point and

sammy [17]

Answer: The freezing point of solution is 16.5°C and the boiling point of solution is 118.2°C

Explanation:

To calculate the molality of solution, we use the equation:

$Molality=\frac{m_{solute}\times 1000}{M_{solute}\times W_{solvent}\text{ in grams}}$

Where,

$m_{solute}$ = Given mass of solute $(S_8)$ = 0.800 g

$M_{solute}$ = Molar mass of solute $(S-8)$ = 256.52 g/mol

$W_{solvent}$ = Mass of solvent (acetic acid) = 100.0 g

Putting values in above equation, we get:

$\text{Molality of solution}=\frac{0.800\times 1000}{256.52\times 100.0}\\\\\text{Molality of solution}=0.0312m$

Calculation for freezing point of solution:

Depression in freezing point is defined as the difference in the freezing point of water and freezing point of solution.

$\Delta T_f=\text{freezing point of acetic acid}-\text{Freezing point of solution}$

To calculate the depression in freezing point, we use the equation:

$\Delta T_f=iK_fm$

or,

$\text{Freezing point of acetic acid}-\text{Freezing point of solution}=iK_fm$

where,

Freezing point of acetic acid = 16.6°C

i = Vant hoff factor = 1 (for non-electrolyte)

$K_f$ = molal freezing point depression constant = 3.59°C/m

m = molality of solution = 0.0312 m

Putting values in above equation, we get:

$16.6^oC-\text{freezing point of solution}=1\times 3.59^oC/m\times 0.0312m\\\\\text{Freezing point of solution}=16.5^oC$

Hence, the freezing point of solution is 16.5°C

Calculation for boiling point of solution:

Elevation in boiling point is defined as the difference in the boiling point of solution and freezing point of pure solution.

The equation used to calculate elevation in boiling point follows:

$\Delta T_b=\text{Boiling point of solution}-\text{Boiling point of acetic acid}$

To calculate the elevation in boiling point, we use the equation:

$\Delta T_b=iK_bm$

or,

$\text{Boiling point of solution}-\text{Boiling point of acetic acid}=iK_fm$

where,

Boiling point of acetic acid = 118.1°C

i = Vant hoff factor = 1 (for non-electrolyte)

$K_f$ = molal boiling point elevation constant = 3.08°C/m

m = molality of solution = 0.0312 m

Putting values in above equation, we get:

$\text{Boiling point of solution}-118.1^oC=1\times 3.08^oC/m\times 0.0312m\\\\\text{Boiling point of solution}=118.2^oC$

Hence, the boiling point of solution is 118.2°C

5 0

3 years ago

What are the 5 indicators of a chemical reaction? What are the 5 indicators of a chemical reaction? I only know 3 for sure:2) Ch

Colt1911 [192]

Temperature change, colour change, releasing gas, bubbles and change in odor

5 0

3 years ago

What feelings do you feel when you hear a song about rain?

dmitriy555 [2]

Answer:

sad..................

3 0

2 years ago

Read 2 more answers

Complete the table to summarize the properties of the different subatomic particles. Type in your answers.

Aloiza [94]

<h2>Complete the table to summarize the properties of the different subatomic particles. </h2>

Explanation:

Atom

It is a smallest particle which cant exist independently.

According To Dalton, atom was indivisible but later on, it was proved that atom can be subdivided into sub atomic particles called electron, proton & neutron.

These subatomic particles have marked properties .

Proton

It was discovered by E.Goldstein .
It is positively charged particle
It is present in nucleus .
Its mass is equal to 1.6726219 × 10⁻²⁷ kilograms

Neutron

It was discovered by E.chadwick .
It is neutral
It is present inside the nucleus .
It's mass is equal to 1.674927471×10⁻²⁷ kg

Electron

It was discovered by J.J Thomson .
It has negative charge .
It's mass is equal to 9.10938356 × 10⁻³¹ kilograms
It is present outside the nucleus in shells .

4 0

2 years ago

Read 2 more answers