Answer:
only 2.5% is fresh water on earth
Answer:
Molar mass of vitamin K = 450.56\frac{g}{mol}[/tex]
Explanation:
The freezing point of camphor = 178.4 ⁰C
the Kf of camphor = 37.7°C/m
where : m = molality
the relation between freezing point depression and molality is
Depression in freezing point = Kf X molality
Where
Kf = cryoscopic constant of camphor
molality = moles of solute dissolved per kg of solvent.
putting values
2.69°C = 37.7°C/m X molality
molality = 0.0714 mol /kg
moles of vitamin K = 0.0714X0.025 = 0.00178 mol
we know that moles are related to mass and molar mass of a substance as:
For vitamin K the mass is given = 0.802 grams
therefore molar mass = 
Answer:
Box is made up of <em>copper</em>, because density is <em>8.96 g/cm³.</em>
Explanation:
Given data:
Volume of box = 17.63 cm³
Mass of box = 158 g
Which metal box is this = ?
Solution:
First we will calculate the density of box then we will compare it with the density value of given metals.
d = m/v
d = 158 g/ 17.63 cm³
d = 8.96 g/cm³
The calculated density is similar to the given density value of copper thus box is made up of copper.
Look at the protons and electrons and rememeber metals want to get rid of electrons to be perfect. Nonmetals are wanting to take in. Metals are negatives in electrons. Opposite for nonmetals.
Answer : The disadvantage of using hydropower is Land can be flooded, displacing people and wildlife
Explanation :
Hydropower is a renewable source of energy. In hydropower, electricity is generated using the mechanical energy of moving water.
Since the kinetic energy is necessary to move the turbines, it is essential that the hydropower plant is present near a water source which has moving water.
It is the most efficient way of harnessing the energy from naturally available energy sources. It does not produce any waste. It does not pollute water or air.
Since hydropower needs kinetic energy of moving water, there is always a possibility of nearby land getting flooded. This would affect the people and wildlife of nearby areas.
Therefore the disadvantage of using hydropower is that land can be flooded, displacing people and wildlife
