Total mass of CaCO3 = 40 amu of Ca + 12amu of C + 16×3 amu of oxygen = 100amu of CaCO3
i.e 100 tonnes of CaCO3 .
mass of CO2 = 12amu of C + 2× 16amu of O = 44 amu of CO2
mass % of CO2 in CaCO3 = (44/100)×100 =44%
i.e
44% of 100 tonnes is CO2.
=44 tonnes of CO2.
therefore, 44% of CO2 is present in CaCO3.
Answer: d. More than 6.5 grams of copper (II) is formed, and some copper chloride is left in the reaction mixture.
Explanation: 
As can be seen from the chemical equation, 2 moles of aluminium react with 3 moles of copper chloride.
According to mole concept, 1 mole of every substance weighs equal to its molar mass.
Aluminium is the limiting reagent as it limits the formation of product and copper chloride is the excess reagent as (14-7.5)=6.5 g is left as such.
Thus 54 g of of aluminium react with 270 g of copper chloride.
1.50 g of aluminium react with=
of copper chloride.
3 moles of copper chloride gives 3 moles of copper.
7.5 g of copper chloride gives 7.5 g of copper.
To answer the problem given:
|0.53−4.0| / 4.0 * 100%
= 3.47 / 4.0 * 100%
= 87%
The maximum theoretical percent recovery from the
crystallization of 4.0 g of acetanilide from 100 ml of water is 87%. I
am hoping that this answer has satisfied your query and it will be able to help
you in your endeavor, and if you would like, feel free to ask another question.
Answer:
is the approximate energy of one photon of this light.
Explanation:
Energy of the photon can be calculated by
(Planck's equation)
where,
E = energy of photon
h = Planck's constant = 
c = speed of light = 
= wavelength of light =
= frequency of the light
we have , 
Now put all the given values in the above formula, we get the energy of the photons.


is the approximate energy of one photon of this light.