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arlik [135]
3 years ago
8

To the nearest whole number how many moles are in 130 g sample of calcium metal?

Chemistry
1 answer:
lesantik [10]3 years ago
6 0
To convert grams to moles, we need the molar mass of the element or compound. remember you can determine the molar mass of a molecule by adding the atomic mass of each atom from the periodic table.

molar mass of Na= 23.0 g/ mol

130 g (1 mol Na/ 23.0 grams)= 5.65 moles or 6 moles.
You might be interested in
In the laboratory you dissolve 13.9 g of potassium phosphatein a volumetric flask and add water to a total volume of 250mL.
tensa zangetsu [6.8K]

Answer:

Molarity of the solution? 0,262 M.

Concentration of the potassium cation? 0,786 M.

Concentration of the phosphate anion? 0,262 M.

Explanation:

Potassium phosphate (K₃PO₄; 212,27 g/mol) dissolves in water thus:

K₃PO₄ → 3 K⁺ + PO₄³⁻ <em>(1)</em>

Molarity is an unit of chemical concentration given in moles of solute (K₃PO₄) per liters of solution.

There are 250 mL of solution≡0,25 L

The moles of K₃PO₄ are:

13,9 g of K₃PO₄ ×\frac{1mol}{212,27 g} = 0,0655 moles of K₃PO₄

The molarity of the solution is:

\frac{0,0655 moles}{0,25L} = 0,262 M

In (1) you can see that 1 mole of K₃PO₄ produces 3 moles of potassium cation. The moles of potassium cation are:

0,0655 moles×3 = 0,1965 moles

The concentration is:

\frac{0,1965 moles}{0,25L} = 0,786 M

The moles of K₃PO₄ are the same than moles of PO₄³⁻, thus, concentration of phosphate anion is the same than concentration of K₃PO₄. 0,262 M

I hope it helps!

4 0
3 years ago
What is the solubility of methylacetylene (in units of grams per liter) in water at 25 °C, when the C3H4 gas over the solution h
Luda [366]

Answer:

The solubility of methylacetylene is 0,11 g L⁻¹

Explanation:

Henry's law is a gas law that states that the amount of dissolved gas in a liquid is proportional to its partial pressure above the liquid.

The formula is:

C = kH P

Where C is solubility of the gas (In mol/L)

kH is Henry constant (9,23x10⁻² mol L⁻¹ atm⁻¹)

An P is partial pressure (0,301 atm)

Solving, C = 2,78x10⁻³ mol L⁻¹. In grams per liter:

2,78x10⁻³ mol L⁻¹ₓ \frac{40 g}{mol} = <em>0,11 g L⁻¹</em>

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I hope it helps!

7 0
3 years ago
The half life of oxygen is 2 minutes. What fraction of a sample of 0.15 will remain after 5 half lives?​
Natasha_Volkova [10]

Answer:

3.13%.

Explanation:

The following data were obtained from the question:

Original amount (N₀) = 0.15

Half life (t½) = 2 mins

Number of half-life (n) = 5

Fraction of sample remaining =.?

Next, we shall determine the amount remaining (N) after 5 half-life. This can be obtained as follow:

Amount remaining (N) = 1/2ⁿ × original amount (N₀)

NOTE: n is the number of half-life.

N = 1/2ⁿ × N₀

N = 1/2⁵ × 0.15

N = 1/32 × 0.15

N = 0.15/32

N = 4.69×10¯³

Therefore, 4.69×10¯³ is remaining after 5 half-life.

Finally, we shall the fraction of the sample remaining after 5 half-life as follow:

Original amount (N₀) = 0.15

Amount remaining (N) = 4.69×10¯³

Fraction remaining = N/N₀ × 100

Fraction remaining = 4.69×10¯³/0.15 × 100

Fraction remaining = 3.13%

3 0
3 years ago
Represente lo que ocurre mediante flechas cuando dos cargas negativas, dos cargas positivas y una carga positiva y otra negativa
pochemuha

Answer:

Neutral.

Explicación:

Cuando dos cargas negativas, dos cargas positivas y una carga positiva y una carga negativa se unen, los átomos se vuelven neutrales porque las cargas opuestas cancelan el efecto de la otra. Si hay igual número de cargas y además son opuestas entre sí, entonces todas estas cargas cancelan el efecto de la otra formando el átomo neutral, pero si hay diferencia en el número de cargas, entonces la carga que es alta en número aparece en el átomos.

8 0
3 years ago
Lina has worked hard to gather data for her experiments. With her last set of data she received, she is ready to publish her pap
nika2105 [10]

43.8 has 3 significant figures and 1 decimal.

<h3 /><h3>What are significant figures?</h3>

The term significant figures refer to the number of important single digits (0 through 9 inclusive) in the coefficient of an expression in scientific notation.

All zeros that occur between any two non-zero digits are significant. For example, 108.0097 contains seven significant digits. All zeros that are on the right of a decimal point and also to the left of a non-zero digit are never significant. For example, 0.00798 contained three significant digits.

Hence, 43.8 has 3 significant figures and 1 decimal.

Learn more about significant figures here:

brainly.com/question/14359464

#SPJ1

8 0
2 years ago
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