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3 years ago

How to calculate the number of atoms, molecules, or ions

1 answer:

8 0

For atoms use a periodic table. The atomic number is the amount of atoms. For molecules and ions look up things revolved around the avogrados principle

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If 40.0 mL of a calcium nitrate solution reacts with excess potassium carbonate to yield 0.524 grams of a precipitate, what is t

tankabanditka [31]

Answer : The molarity of calcium ion on the original solution is, 0.131 M

Explanation :

The balanced chemical reaction is:

$Ca(NO_3)_2+K_2CO_3\rightarrow CaCO_3+3KNO_3$

When calcium nitrate react with potassium carbonate to give calcium carbonate as a precipitate and potassium nitrate.

First we have to calculate the moles of $CaCO_3$

$\text{Moles of }CaCO_3=\frac{\text{Mass of }CaCO_3}{\text{Molar mass of }CaCO_3}$

Given:

Mass of $CaCO_3$ = 0.524 g

Molar mass of $CaCO_3$ = 100 g/mol

$\text{Moles of }CaCO_3=\frac{0.524}{100g/mol}=0.00524mol$

Now we have to calculate the concentration of $CaCO_3$

$\text{Concentration of }CaCO_3=\frac{\text{Moles of }CaCO_3}{\text{Volume of solution}}=\frac{0.00524mol}{0.040L}=0.131M$

Now we have to calculate the concentration of calcium ion.

As, calcium carbonate dissociate to give calcium ion and carbonate ion.

$CaCO_3\rightarrow Ca^{2+}+CO_3^{2-}$

So,

Concentration of calcium ion = Concentration of $CaCO_3$ = 0.131 M

Thus, the concentration or molarity of calcium ion on the original solution is, 0.131 M

4 0

3 years ago

How does this process appear in the atmosphere?

Mariulka [41]

D.The transferring of thermal energy from the sun to the earth!

8 0

3 years ago

Read 2 more answers

Most gases ______________ .

kompoz [17]

Answer is D, they are compressible

5 0

3 years ago

If an atom has 5 protons and 6 neutrons how many electrons does it have? What would the mass of this atom be?

ExtremeBDS [4]

5 electrons
Mass would be 11

3 0

3 years ago

How are pH and pOH ?

bija089 [108]

Answer:

B. pOH = 14 - pH and D. pH = 14 - pOH.

Explanation:

Hello,

In this case, we must remember that pH and pOH are referred to a measure of acidity and basicity respectively, since pH accounts for the concentration of H⁺ and pOH for the concentration of OH⁻ in a solution. In such a way, since the maximum scale is 14, we say that the addition between the pH and pOH must be 14:

$pH+pOH=14$

Therefore, the correct answers are B. pOH = 14 - pH and D. pH = 14 - pOH since the both of them are derived from the previous definition.

Best regards.

6 0

3 years ago