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ryzh [129]
2 years ago
12

When does the composition of a substance does not change?

Chemistry
1 answer:
blagie [28]2 years ago
4 0
I think when it does not react with anything I think
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If 0.35 moles of kcl was dissolved in enough water to make 0.2 L of solution, what is molarity?
Mars2501 [29]

Answer:

1.75M

Explanation:

molarity = number of moles of solute/ number of L of solution =

=0.35 mol/0.2L = 1.75 mol/L = 1.75 M

8 0
3 years ago
calculate the number of moles of gas that occupy a 3.45L container at a pressure of 1.48 atm and a temperature of 45.6 Celsius ​
Otrada [13]

Answer:

There are 0,2 moles of gas that ocuppy the container.

Explanation:

We apply the formula of the ideal gases, we clear n (number of moles); we use the ideal gas constant R = 0.082 l atm / K mol. Firs we convert the unit of temperature in Celsius into Kelvin:

0°C= 273 K ------> 45,6 °C= 273 + 45, 6= 318, 6 K

PV= nRT ---> n= PV/RT

n= 1,48 atm x 3,45 L /0.082 l atm / K mol x 318,6 K

n= 0,195443479 mol

8 0
3 years ago
Cómo se forma el enlace ionico​
scoundrel [369]

Answer:

El enlace iónico se forma por transferencia de electrones entre metales y no metales. El enlace covalente se forma al compartir electrones entre no metales.

Explanation:

5 0
3 years ago
A sample of paper from an ancient scroll was found to contain 39.5% 14C content as compared to a present-day sample. The t1/2 fo
nirvana33 [79]

Answer

7665 years

Procedure

Let N₀ be the amount of carbon-14 present in a living organism. According to the radioactive decay law, the number of carbon-14 atoms, N, left in a dead tissue sample after a certain time, t, is given by the exponential equation:

N = N₀e^(-λt)

where λ is the decay constant which is related to half-life (T1/2) by the equation:

\lambda=\frac{ln(2)}{t_{\frac{1}{2}}}

Here, ln(2) is the natural logarithm of 2.

The percent of carbon-14 remaining after time t is given by N/N₀.

Using the first equation, we can determine λt.

The half-life of carbon-14 is 5,720 years, thus, we can calculate λ using the second equation, and then find t.

\lambda=\frac{ln(2)}{5720}=1.211\times10^{-4}

Solving the second equation for t, and using the λ we have just calculated we will have

t= 7665 years

3 0
11 months ago
What is ammonification?
juin [17]
Ammonification is performed by bacteria to convert organic nitrogen to ammonia.
4 0
3 years ago
Read 2 more answers
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