a. Elemental percent composition is the mass percent of each element in the compound.
The formula for mass elemental percent composition = (1)
The molecular formula of cisplatin is .
The atomic weight of the elements in cisplatin is:
Platinum,
Nitrogen,
Hydrogen,
Chlorine,
The molar mass of = =
The mass of each element calculated using formula (1):
- Platinum, %
%.
- Nitrogen, %
%
- Hydrogen, %
%
- Chlorine, %
%
b. The given reaction of cisplatin is:
According to the balanced reaction, 1 mole of gives 1 mole of .
Now, calculating the number of moles of in 100.0 g.
Number of moles =
Molar mass of =
Number of moles of = .
Since, 1 mole of gives 1 mole of . Therefore, mass of cisplatin is:
For mass of :
Molar mass of =
Since, 1 mole of gives 2 mole of . Therefore, mass of is:
So if the compound has the smallest gram formula mass it has the highest percentage composition by mass of strontium
Answer:
0.00230 = <u>3 significant figures</u>
Explanation:
Significant digits or figures of a given number are the digits or figures that have meaning and contributes to the precision of the given number.
Therefore, <u>0.00230 = 3 significant figures.</u>
Reason: The non-zeros figures and the trailing zero after the decimal are significant. Whereas, all the leading zeros are not considered significant.
Answer:
2.2 °C/m
Explanation:
It seems the question is incomplete. However, this problem has been found in a web search, with values as follow:
" A certain substance X melts at a temperature of -9.9 °C. But if a 350 g sample of X is prepared with 31.8 g of urea (CH₄N₂O) dissolved in it, the sample is found to have a melting point of -13.2°C instead. Calculate the molal freezing point depression constant of X. Round your answer to 2 significant digits. "
So we use the formula for <em>freezing point depression</em>:
In this case, ΔTf = 13.2 - 9.9 = 3.3°C
m is the molality (moles solute/kg solvent)
- 350 g X ⇒ 350/1000 = 0.35 kg X
- 31.8 g Urea ÷ 60 g/mol = 0.53 mol Urea
Molality = 0.53 / 0.35 = 1.51 m
So now we have all the required data to <u>solve for Kf</u>: