Answer:
0.144 kg of water
Explanation:
From Raoult's law,
Mole fraction of solvent = vapor pressure of solution ÷ vapor pressure of solvent = 423 mmHg ÷ 528.8 mmHg = 0.8
Let the moles of solvent (water) be y
Moles of solute (C3H8O3) = 2 mole
Total moles of solution = moles of solvent + moles of solute = (y + 2) mol
Mole fraction of solvent = moles of solvent/total moles of solution
0.8 = y/(y + 2)
y = 0.8(y + 2)
y = 0.8y + 1.6
y - 0.8y = 1.6
0.2y = 1.6
y = 1.6/0.2 = 8
Moles of solvent (water) = 8 mol
Mass of water = moles of water × MW = 8 mol × 18 g/mol = 144 g = 144/1000 = 0.144 kg
Answer:
the answer is
B)It was the first planet located through mathematical calculations
Musical instruments use resonance to amplify the sound and make the sounds louder
Answer:
specifically 30º west of the north
Explanation:
This exercise can be solved using the composition of vectors, let's call the speed of the river that goes east (v₁ = 8 mi / h) to the speed of the boat (v₂ = 16 mi / h) and the desired speed from south to north (v₃ =?). Look at the attachment to be clear about the vectors
Let's use the Pythagorean triangle
v₃² = v₁² + v₂²
Let's calculate v₂
v₂² = v₃² - v₁²
v₂ = √ (16² - 8²)
v₂ = 13.86 mi / h
To find the angle we use trigonometry
sin θ = v1 / v3
θ = sin⁻¹ (v1 / v3)
θ = sin⁻¹ (8/16)
θ = 30º
The boat must be pointed at 30º with respect to the south-north direction, specifically 30º west of the north
