Answer:
<h2>0.75 g/mL</h2>
Explanation:
The density of a substance can be found by using the formula
From the question we have
We have the final answer as
<h3>0.75 g/mL</h3>
Hope this helps you
An mL is also equivalent to cm³, signifying that 140 mL is equivalent to 140 cm³. The mass of ethanol is calculated by multiplying the density by the volume.
mass = (140 cm³)(0.789 g/cm³)
mass = 110.46 g
Then, calculate the number of moles of ethanol by dividing the mass by the molar mass of ethanol equal to 46.07 g/mol.
number of moles = (110.46 g/ 46.07 g/mol) = 2.4 mol
Then, multiply the number of moles by the Avogadro's number.
2.4 mol (6.022 x 10²³)
<em> number of molecules = 1.445 x 10²⁴</em>
Answer:
A. 1613 °C
Explanation:
The asthenosphere is located just below the Earth’s crust.
It must be molten or semi-molten, so that convection currents can move the tectonic plates above it.
Rocks start to melt at about 1300 °C, so a temperature of 1613 °C sounds about right.
When dT = Kf * molality * i
= Kf*m*i
and when molality = (no of moles of solute) / Kg of solvent
= 2.5g /250g x 1 mol /85 g x1000g/kg
=0.1176 molal
and Kf for water = - 1.86 and dT = -0.255
by substitution
0.255 = 1.86* 0.1176 * i
∴ i = 1.166
when the degree of dissociation formula is: when n=2 and i = 1.166
a= i-1/n-1 = (1.166-1)/(2-1) = 0.359 by substitution by a and c(molality) in K formula
∴K = Ca^2/(1-a)
= (0.1176 * 0.359)^2 / (1-0.359)
= 2.8x10^-3
Answer:
eye weakness is caused by deficiency of vitamin A
