Which of the following BEST supports the Big bang theory of the origin of the universe?

A solution of phosphoric acid was made by dissolving 10.0 g of H3PO4 in 100.0 mL of water. The resulting volume was 113 mL. Calc

rodikova [14]

Explanation:

Mass of solute = 10.0 g

mass of solvent(water) = m

Volume of solvent( water) = v = 100.0 mL

Density of water= d = $1 g/cm^3=1 g/mL$

$1 mL= 1 cm^3$

$m=d\times v=1.0 g/mL\times 100.0 = 100.0 g$

Mass of solution(M) = Mass of solute + mass of solvent

M = 10.0 g + 100.0 g = 110.0 g

Volume of the solution = V = 113 mL

Density of the solution = D

$D=\frac{M}{V}=\frac{110.0 g}{113 mL}=0.9734 g/mL$

The density of the solution is 0.9734 g/ml.

Moles of phosphoric acid = $n_1=\frac{10.0 g}{98 g/mol}=0.1020 mol$

Moles of water = $n_2=\frac{100.0 g}{18g/mol}=5.556 mol$

Mole fraction of phosphoric acid = $\chi_1$

$\chi_1=\frac{n_1}{n_1+n_2}=\frac{0.1020 mol}{0.1020 mol+5.556 mol}$

$\chi_1=0.01803$

Mole fraction of water = $\chi_2$

$\chi_2=\frac{n_2}{n_1+n_2}=\frac{5.556 mol}{0.1020 mol+5.556 mol}$

$\chi_2=0.9820$

$[Molarity]=\frac{\text{Moles of solute}}{\text{Volume of solution(L)}}$

Moles of phosphoric acid = 0.1020 mol

Volume of the solution = V = 113 mL = 0.113 L ( 1 mL = 0.001 L)

Molarity of the solution :

$=\frac{0.1020 mol}{0.113 L}=0.903 M$

$[Molality]=\frac{\text{Moles of solute}}{\text{Mass of solvent(kg)}}$

Moles of phosphoric acid = 0.1020 mol

Mass of solvent(water) = m =100.0 g = 0.100 kg ( 1 g = 0.001 kg)

Molality of the solution :

$=\frac{0.1020 mol}{0.100 kg}=1.02 mol/kg$

6 0

3 years ago

What are the SI units for specific heat capacity

KATRIN_1 [288]

The SI unit for specific heat capacity is the joule per kilogram Kelvin, J?kg-1?K-1 or J/(kg?K), which is the amount of energy required to raise the temperature of one kilogram of the substance by one Kelvin

7 0

3 years ago

Read 2 more answers

Help me pls

harkovskaia [24]

Answer:

this is answers to the second picture

Explanation:

1- energy

2- structure

3- reaction

4- substance

5- reactants

6- products

7- changed

8- At first there is no reaction because of the protective oxide coating on the aluminum. But soon an exothermic reaction between bromine and aluminum causes brown fumes of bromine to be given off. But as a new substance, aluminum bromide is produced. White smoke is produced.

9- heated to 120 degrees Celsius it melts and first forms a pale-yellow liquid.

In this form the atoms are covalently bonded, and the liquid can flow easily. However, heated up beyond 150 degrees Celsius, the result is a dark red

10- When a chemical change occurs it is more difficult to revert the substance back to its original state. (To be honest I don't know)

3 0

3 years ago

If there is currently 50kg of U-235 present in Oklo, how much must have been present 750 million years ago when the reaction too

Viefleur [7K]

To answer this question, you need to know the concept of half-life, which is how a radioactive material decreases in mass over time.

The half life of U-235 is 703.8 million years. The first part of this problem is to find the scale factor. To do this, divide the time that has past by the half life, like this:

$\frac{750}{703.8} = 1.066$
Now, take this scale factor and multiply it by the current mass, like this:

$50 \times 1.066 = 53.3$
This number is what you add to the current mass to get the original mass. That is because the scale factor showed us that it was just over one half life. Since after one half life, the mass is cut in half, and this is over one half life, when we add to the original it will be a little over double. This equation illustrates the final addition:

$50 + 53.3 = 103.3$
I hope this helped you. Fell free to ask any further questions.

7 0

3 years ago

Which is produced in a synthesis reaction?

olga55 [171]

Answer: a single compound

Explanation: I know it

6 0

3 years ago