Answer:
0.297 °C
Step-by-step explanation:
The formula for the <em>freezing point depression </em>ΔT_f is
ΔT_f = iK_f·b
i is the van’t Hoff factor: the number of moles of particles you get from a solute.
For glucose,
glucose(s) ⟶ glucose(aq)
1 mole glucose ⟶ 1 mol particles i = 1
Data:
Mass of glucose = 10.20 g
Mass of water = 355 g
ΔT_f = 1.86 °C·kg·mol⁻¹
Calculations:
(a) <em>Moles of glucose
</em>
n = 10.20 g × (1 mol/180.16 g)
= 0.056 62 mol
(b) <em>Kilograms of water
</em>
m = 355 g × (1 kg/1000 g)
= 0.355 kg
(c) <em>Molal concentration
</em>
b = moles of solute/kilograms of solvent
= 0.056 62 mol/0.355 kg
= 0.1595 mol·kg⁻¹
(d) <em>Freezing point depression
</em>
ΔT_f = 1 × 1.86 × 0.1595
= 0.297 °C
Answer:
(x + 2)(x + 2)
Explanation:
You need 2 numbers that times to give 4 and add to give 4. So 2 and 2.
There are 1,000 milligrams (mg) in one gram:
In 10 grams, there are 10 x 1,000 = 10,000 milligrams. This is a lethal dose of caffeine.
There are 4.05 mg/oz (milligrams/ounce) of caffeine in the soda.
In a 12 ounce can, there are 4.05 x 12 = 48.6 milligrams.
How many sodas would it take to kill you?
To find this, we divide the lethal dose amount (10,000 mg) by the amount of caffeine per can (48.6 mg).
10,000 ÷ 48.6 = 205.76.
Since 205 cans is not quite 10,000 mg, technically it would take 206 cans of soda to consume a lethal dose of caffeine.
