Answer:
21 g/mL
Explanation:
To solve this problem, first look at the density equation, which is D=M/V, which D stands for density, M stands for mass, and V stands for volume. When you substitute in the variables, you get D=17.5/.82, which is equivalent to 21.34. However, since we need to pay attention to the sig fig rules for multiplying, we need to have the same amount of sig figs as the value with the least amount of sig figs, which is the number .82. .82 has two sig figs, so you round down. Your answer will be 21 g/mL.
Answer:
ΔS° = - 47.2 J/mol.K
Explanation:
ΔS°= 4(S°mH3PO4) - 6(S°mH2O) - S°mP4O10
∴ S°mH2O(l) = 69.9 J/mol.K
∴ S°mP4O10 = 231 J/mol.K
∴ S°mH3PO4 = 150.8 J/mol.K
⇒ ΔS° = 4*(150.8) - 6*(69.9) - 231
⇒ ΔS° = - 47.2 J/mol.K
<u>Answer:</u> The amount of heat released is 56 MJ.
<u>Explanation:</u>
To calculate the number of moles, we use the equation:
Given mass of 
= 12 kg = 12000 g (Conversion factor: 1 kg = 1000 g)
Molar mass of = 30 g/mol
Putting values in above equation, we get:
The chemical reaction for hydrogenation of ethene follows the equation:
By Stoichiometry of the reaction:
When 1 mole of ethane releases 140 kJ of heat.
So, 400 moles of ethane will release = 
of heat.
Converting this into Mega joules, using the conversion factor:
1 MJ = 1000 kJ
So, 
Hence, the amount of heat released is 56 MJ.
Answer;
=28.09 amu
Explanation;
In this problem, they did not give us the percentages. However, since we know the number of atoms, we can easily calculate the percentages. For example:
(460 X 100)/500 = 92%
If we do this for all three isotopes,
(460 × 25)/500 = 5 %
(460 × 15) /500 = 3%
-We get 92%, 5%, and 3%. (We'll assume these are absolute numbers for determining our significant figures).
Now the problem is just like the previous one. First convert the percentages into decimals. Then multiply those decimals by the masses and add. Here's the solution:
= (0.92) X (27.98 amu) + (0.05) X (28.98 amu) + (0.03) X (29.97 amu)
= 25.74 amu + 1.449 amu + 0.8991 amu
= 28.09 amu
