Answer: C) 0.020 m
Explanation:
Molality of a solution is defined as the number of moles of solute dissolved per kg of the solvent.
where,
n = moles of solute
= weight of solvent in g
Mole fraction of is =
i.e.
moles of
is present in 1 mole of solution.
Moles of solute =
moles of solvent (water) = 1 - = 0.99
weight of solvent =
Molality =
Thus approximate molality of in this solution is 0.020 m
Answer:
Explanation:
The net force on electron is electrostatic force between electron and proton in the nucleus .
Fc =
This provides the centripetal force for the circular path of electron around the nucleus .
Centripetal force required =
So
Answer:
The total photons required = 5.19 × 10²⁸ photons
Explanation:
Given that:
the radiation wavelength λ= 12.5 cm = 0.125 m
Volume of the container = 0.250 L = 250 mL
The density of water = 1 g/mL
Density = mass /volume
Mass = Volume × Density
Thus; the mass of the water = 250 mL × 1 g/mL
the mass of the water = 250 g
the specific heat of water s = 4.18 J/g° C
the initial temperature = 20.0° C
the final temperature = 99° C
Change in temperature = (99-20)° C = 79 ° C
The heat q absorbed during the process = ms
The heat q absorbed during the process = 250 g × 4.18 J/g° C × 79° C
The heat q absorbed during the process = 82555 J
The energy of a photon can be represented by the equation :
= hc/λ
where;
h = planck's constant =
c = velocity of light =
=
= J
The total photons required = Total heat energy/ Energy of a photon
The total photons required =
The total photons required = 5.19 × 10²⁸ photons