Advantages
Solar energy is a clean and renewable energy source.Once a solar panel is installed, solar energy can be produced free of charge.Solar energy will last forever whereas it is estimated that the world’s oil reserves will last for 30 to 40 years.Solar energy causes no pollution.Solar cells make absolutely no noise at all. On the other hand, the giant machines utilized for pumping oil are extremely noisy and therefore very impractical.Very little maintenance is needed to keep solar cells running. There are no moving parts in a solar cell which makes it impossible to really damage them.In the long term, there can be a high return on investment due to the amount of free energy a solar panel can produce, it is estimated that the average household will see 50% of their energy coming in from solar panels.
Disadvantages
Solar panels can be expensive to install resulting in a time-lag of many years for savings on energy bills to match initial investments.Electricity generation depends entirely on a countries exposure to sunlight; this could be limited by a countries climate.Solar power stations do not match the power output of similar sized conventional power stations; they can also be very expensive to build.Solar power is used to charge batteries so that solar powered devices can be used at night. The batteries can often be large and heavy, taking up space and needing to be replaced from time to time.
A ammonia as it has the least molar mass
Uranium, which is number 92
Answer:
30 moles of ethanol are needed to prepare a 25 m solution, using 1200 g of water
Explanation:
This a short problem of solutions:
Our solute is ethanol: C₂H₅OH
Our solvent is water-
25 m, is our solution's concentration. m means molality (moles of solute contained in 1kg of solvent).
Our solvent mass is 1200g. We convert them to kg
1200 g . 1kg / 1000g = 1.2 kg
m = mol/kg → mol = m . kg
mol = 25 mol/kg . 1.2kg →30 moles
Answer:
1.48 M
Explanation:
Step 1:
The balanced equation for the reaction. This is given below:
Mg + H2SO4 —> MgSO4 + H2
Step 2:
Determination of the number of mole of Mg in 80.0 mL of 0.200 M Mg solution. This is illustrated below:
Molarity of Mg = 0.200 M
Volume of solution = 80 mL = 80/1000 = 0.08L
Mole of Mg =?
Molarity = mole /Volume
0.2 = mole /0.08
Mole = 0.2 x 0.08
Mole of Mg = 0.016 mole.
Step 3:
Determination of the number of mole of H2SO4 that reacted. This is illustrated below:
Mg + H2SO4 —> MgSO4 + H2
From the balanced equation above,
1 mole of Mg reacted with 1 mole of H2SO4.
Therefore, 0.016 mole of Mg will also react with 0.016 mole of H2SO4.
Step 4:
Determination of the concentration of the acid.
Mole of H2SO4 = 0.016 mole.
Volume of acid solution = 10.8 mL = 10.8/1000 = 0.0108 L
Molarity =?
Molarity = mole /Volume
Molarity = 0.016/0.0108
Molarity of the acid = 1.48 M
Therefore, the concentration of acid is 1.48 M
