I’m pretty sure the answer is D :)
Answer:
Rubidium is used in vacuum tubes as a getter, a material that combines with and removes trace gases from vacuum tubes. It is also used in the manufacture of photocells and in special glasses. Since it is easily ionized, it might be used as a propellant in ion engines on spacecraft.
Symbol: Rb (37)
Atomic Weight: 85.4678
Atomic Number: 37
Number of Stable Isotopes: 1 (View all isotope .
Critical pressure is the pressure of a gas or vapor in its critical state and critical point is a point on a phase diagram at which both the liquid and gas phases of a substance have the same density, and are therefore indistinguishable.
Answer:
130.4 grams of sucrose, would be needed to dissolve in 500 g of water.
Explanation:
Colligative property of boiling point elevation:
ΔT = Kb . m . i
In this case, i = 1 (sucrose is non electrolytic)
ΔT = Kb . m
0.39°C = 0.512°C/m . m
0.39°C /0.512 m/°C = m
0.762 m (molality means that this moles, are in 1kg of solvent)
If in 1kg of solvent, we have 0.712 moles of sucrose, in 500 g, which is the half, we should have, the hallf of moles, 0.381 moles
Molar mass sucrose = 342.30 g/m
Molar mass . moles = mass
342.30 g/m . 0.381 m = 130.4 g
1. The balanced equation tells us that 2 moles of H2S produce 2 moles of H2O.
8.3 moles H2S x (2 moles H2O / 2 moles H2S) = 8.3 moles H2O = theoretical amount produced
8.3 moles H2O x (18.0 g H2O / 1 mole H2O) = 149 g H2O produced theoretically
% yield = (actual amount produced / theoretical amount) x 100 = (137.1 g / 149 g) x 100 = 91.8 % yield
2. Calculate moles of each reactant.
150.0 g N2 x (1 mole N2 / 28.0 g N2) = 5.36 moles N2
32.1 g H2 x (1 mole H2 / 2.02 g H2) = 15.9 moles H2
The balanced equation tells us that we need 3 moles of H2 to react with every 1 mole of N2.
So if we have 5.36 moles N2, we need 3x that = 16.1 moles H2. Do we have that much available? No, just under at 15.9 moles. So H2 is the limiting reactant. At the end of the reaction there will be a little N2 left over.
