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4 years ago

1. What is the mass of 105.00 moles of H20?

2 answers:

5 0

The average mass of one H2O molecule is 18.02 amu. The number of atoms is an exact number, the number of mole is an exact number; they do not affect the number of significant figures. The average mass of one mole of H2O is 18.02 grams. This is stated: the molar mass of water is 18.02 g/mol.

Explanation:

alexandr1967 [171]4 years ago

3 0

Answer:

1891.575 g.

Explanation:

The molar mass of water = 2 * 1.008 + 15.999 = 18.015 g.

So 105 moles = 1891.575 g.

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7) Convert 8.34 x 10^-6 Kg to cg"

marusya05 [52]

The answer is .00834 cg hopefully this helped

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3 years ago

Why is U-235 the most common nuclear fuel instead of the more abundant U-238? State a clear topic sentence and support it with e

GREYUIT [131]

<h3>Answer and explanation;</h3>

The isotope U-235 is an important common nuclear fuel because under certain conditions it can readily be split, yielding a lot of energy. It is therefore said to be 'fissile' and use the expression 'nuclear fission'.
Uranium 238 on the other hand is not fissionable by thermal neutrons, but it can undergo fission from fast or high energy neutrons. Hence it is not fissile, but it is fissionable.
In a nuclear power station fissioning of uranium atoms replaces the burning of coal or gas. Heat created by splitting the U-235 atoms is then used to make steam which spins a turbine to drive a generator, producing electricity.

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3 years ago

How Earth and the sun move in space relative to each other

liberstina [14]

The two theories were:

1.Geocentric theory stating that earth is the centre of the universe and sun revolves around it.

2.Heliocentric theory stating that the earth revolves around the sun.

6 0

3 years ago

Purification of copper can be achieved by electrorefining copper from an impure copper anode onto a pure copper cathode in an el

Likurg_2 [28]

Answer: 281 hours

Explanation:-

1 electron carry charge= $1.6\times 10^{-19}C$

1 mole of electrons contain= $6.023\times 10^{23}$ electrons

Thus 1 mole of electrons carry charge= $\frac{1.6\times 10^{-19}}{1}\times 6.023\times 10^{23}=96500C$

$Cu^{2+}+2e^-\rightarrow Cu$

$96500\times 2=193000Coloumb$ of electricity deposits 1 mole or 63.5 g of copper

0.0635 kg of copper is deposited by 193000 Coloumb

11.5 kg of copper is deposited by= $\frac{193000}{0.0635}\times 11.5=34952756$ Coloumb

$Q=I\times t$

where Q= quantity of electricity in coloumbs = 34952756 C

I = current in amperes = 34.5 A

t= time in seconds = ?

$34952756 C=34.5A\times t$

$t=1013123sec=281hours$

Thus it will take 281 hours to plate 11.5 kg of copper onto the cathode if the current passed through the cell is held constant at 34.5 A.

8 0

3 years ago

What is the delta H fusion used to calculate volume of a liquid frozen that produces 1 kg of energy?

gulaghasi [49]

Answer:

The correct option is C. 1 kJ x 1/ΔHfus x g/mol x ml/g liquid

Explanation:

The change in enthalpy of fusion (ΔHfus) has units of energy divided into moles of substance:

ΔHfus = energy/mol of substance = J/mol or KJ/mol

Thus, we multiply the kJ of energy produced by the inverse of ΔHfus (in kJ/mol) we obtain the moles of substance:

energy (kJ) x 1/ΔHfus (mol/kJ) = moles of substance(mol)

Then, if we multiply the moles of substance by the molecular weight of the substance (in g/mol) we obtain the grams:

moles of substance(mol) x molecular weight (g/mol) = grams of substance (g)

Finally, if we multiply the grams of substance (in g) by the density of the substance (in g/ml) we obtain the volume (in ml):

grams of substance (g) x 1/density (ml/g) = volume (ml)

We combine all these parts to obtain the equation for the volume required to produce 1 kJ of energy:

energy (kJ) x 1/ΔHfus (mol/kJ) x molecular weight (g/mol) x 1/density (ml/g)

Therefore, the correct option is:

C → 1 kJ x 1/ΔHfus x g/mol x ml/g liquid

5 0

3 years ago

Read 2 more answers