I think there are a bond??
Answer:
360.22 Torr
Explanation:
In this case, we need to use the Raoult Law expression for vapour pressure which is the following:
Ps = Xw * P°w
Ps: Pressure of solution
Xw: molar fraction of water
P°w: vapour pressure of water.
Of course this expression is only usable in cases like this, when we have solutions with non volatile solutes like this one.
Now, we have the pressure of water but not the molar fraction. This can be calculated using the masses and then, calculating the moles.
the moles of each reagent here, using the molar masses, which are 18 g/mol for water and 134 g/mol for dyglime:
nw = 100 / 18 = 5.56 moles
nd = 150 / 134 = 1.12 moles
Now the molar fraction can be done using the following expression:
X = na / na + nb
We have the moles of each compound, so, the molar fraction for water it would be:
Xw = 5.56 / (5.56+1.12) = 0.83
Finally, we can calculate the vapour pressure of solution Ps:
Ps = 0.83 * 434
Ps = 360.22 Torr
The units tell you:
g/cm³ = Mass (in grams) per (divided by) Volume (in cm³);
So:
109/24 = 4.54166..... ⇒ 4.54 g/cm³.
Always look at the units.
Just like for speed, you might have m/s so this is:
Distance (in meters) per (divided by) Time (in seconds).
Answer:
The correct answer is 0.78 m
Explanation:
Molality is defined as moles of solute per kilogram of solvent and it is expressed as mol/kg. In this case, the solute is the compound (with a molecular weight of 226.9) and the solvent is water.
First, we calculate the number of moles of compound we have in solution. For this, we divide the mass of compound into the molecular weight:
moles solute = 22.1 g x 1 mol/226.9 g= 0.097 mol
We have 0.097 moles of compound in 250 g of solvent (water) and we want to know the moles in 1000 g (1000 g= 1 kg):
0.097 mol x 1000 g/250g= 0.779 mol/kg = 0.078 m
Every 2 million years the amount is halved
0 million = 200g
2 million = 200g/2 = 100g
4 million = 100g/2 = 50g