Answer:
1.195 g of Arsenic.
Explanation:
Equation of the reaction:
Ga(l) + As(s) → GaAs(s).
Calculating the limiting reagent by:
Number of moles of:
Gallium:
Molar mass of Gallium = 69.7 g/mol.
Mass = 4 g
Number of moles = mass/molar mass
= 4/69.7
= 0.0574 mol.
Arsenic:
Molar mass of Arsenic = 75 g/mol.
Mass = 5.5 g
Number of moles = mass/molar mass
= 5.5/75
= 0.0733 mol
Therefore, using stoichiometry since 1 mole of Gallium reacted with 1 mole of Arsenic. The limiting reagent is Gallium.
Excess reagent is Arsenic.
Number of moles excess = 0.0733 - 0.0574
= 0.0159 moles
Mass of the excess Arsenic left =
Molar Mass * number of moles
= 0.0159 * 75
= 1.195 g of Arsenic.
Answer:
2 CO + O2 ———————-> 2 CO2
Mass of CO = 174 g
First change it into moles
No of moles = (mass in grams)/molar mass
Molar mass of CO = 30 g/mol
No of moles of CO = 174/30 = 5.8 mol
2 CO + O2 ———————-> 2 CO2
Equation shows that
2 moles of CO react with moles of O2 = 1 mol
1 mole of CO react with moles of O2 = 1/2
1 mole of CO react with moles of O2 = 0.5 mol
5.8 mole of CO react with moles of O2 =0.5x5.8
5.8 mole of CO react with moles of O2 = 2.9 mol
No of moles of O2 used = 2.9 mol
Then change it into no of molecules
No of molecules of O2 = 2.9x6.02x10^23
No of molecules of O2 used = 17.45x10^23
Explanation:
Answer:
In order to take steps by humans for controlling the change in climate.
Explanation:
It is important that scientist find out the change which occurs in the climate with the passage of time by performing experiments and also repeat the experiments in order to verify their findings. Due to these experiments, scientists also find out the reasons behind of climate change which enable us to take steps in preventing the change that occurs in the environment. it is also important for scientists to be able to explain how they know that climate has changed over time in order to explain that he is not assuming or making predictions, he has to provide evidence for his statement which is only be possible through experiments.
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