Answer: 3.35x10²³atoms H2
Explanation: solution attached:
Convert mass of Al to moles
Do the mole to mole ratio between Al and H2
Convert moles of H2 to atoms using Avogadro's number.
Density (d) which is the quotient when mass (m) is divided by volume (v) is usually reported in terms of g/mL.
d = m /v
Substituting the known values,
d = (1.62 kg) x (1000 g/ 1 kg) / (205 mL)
The answer would be approximately equal to 7.9 g/mL.
From the calculations, the heat of fusion of the substance is 0.73 kJ
<h3>What is is the heat of freezing?</h3>
The heat of freezing is the energy released when the substance is converted from liquid to solid.
Now we know that the molar mass of the substance is 82.9 g/mol hence the number of moles of the substance is; 13.3 g /82.9 g/mol = 0.16 moles
Now the heat of fusion shall be;
H = 4.60 kj/mol * 0.16 moles
H = 0.73 kJ
Learn more about freezing:brainly.com/question/3121416
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Answer:
If you continue to cool water past 4 degrees Celsius, its density starts to plummet (you can see this in the graph). At zero degrees, i.e., the temperature at which water turns into ice, the density of water is actually quite low. It turns out that ice has a lower density than water, and any object that has a lower density than the liquid form on which it’s kept (in this case, water) will be able to float!
Explanation:
Answer:- D. Double- replacement reaction
Explanations:- In general, the decomposition reactions looks like:

The given reaction looks different than this and so it is not decomposition reaction.
A single-replacement reaction looks like:

Our reaction looks different from this so single-replacement is also not correct.
Synthesis reaction looks exactly opposite to decomposition reaction.

The given reaction is different than this and so it is not synthesis reaction also.
A double-replacement reaction looks like:

In this reaction, the ions are exchanged as could be seen in the general reaction. On reaction side,A is with B and C is with D. On product side, A is with D and C is with B.
The same is happening in the given reaction. Nitrate ion is with lead metal on reactant side and chlorine is with hydrogen, On product side, Chlorine is with lead metal and nitrate ion is with hydrogen. So, ion exchange has taken place here and so this is a double-replacement reaction and choice D is correct.