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>:
Answer:
Molecules must collide with sufficient energy, known as the activation energy, so that chemical bonds can break. Molecules must collide with the proper orientation. A collision that meets these two criteria, and that results in a chemical reaction, is known as a successful collision or an effective collision.
Answer:
The molar mass of a compound is The mass in grams of 1 mole of the compound (Option A)
Explanation:
Let's take ammonia as an example (NH3)
Mass of N = 14 g
Mass of H = 1 g
Molar mass of ammonia is Mass of N + (Mass of H).3
14 + 3 = 17 g/m
Ammonia is a compound that has 1 mol of N, plus 3 moles of H (see the formula)
The number of atoms in 1 mole of the compound --> This is Avogadro
M/V=D
65.14/35.4≈1.84
The density of the sulfuric acid would be about 1.84g/mL
