Answer :
The parent and daughter concentrations (in percentages) is, 60 % and 40 % respectively.
The age of rock is
Explanation :
First we have to calculate the parent and daughter concentrations (in percentages).
and,
As we know that, the half-life of uranium-238 = years
Now we have to calculate the rate constant, we use the formula :
Now we have to calculate the time passed.
Expression for rate law for first order kinetics is given by:
where,
k = rate constant =
t = time passed by the sample = ?
a = initial amount of the reactant = 3 g
a - x = amount left after decay process = 1.8 g
Now put all the given values in above equation, we get
Therefore, the age of rock is
b. CH₃CH(Br)CH(Br)CH₃
c. CH₃CH₂CH(Br)CH₃
d. CH₃CH₂CH₂COOH
e. CH₃CH₂CH₂CH₃
The required moles of CaO are needed to react with an excess of water to form 370 grams of calcium hydroxide is 280g.
Relation between the mass and moles of any substance will be represented as:
n = W/M, where
Given chemical reaction is:
CaO + H₂O → Ca(OH)₂
Moles of Ca(OH)₂ = 370g / 74g/mol = 5mol
From the stoichiometry of the reaction, 5 moles of CaO is required to produce 5 moles of Ca(OH)₂.
Mass of CaO = (5mol)(56g/mol) = 280g.
Hence required mass of CaO is 280g.
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Answer:
Explanation:
Formal charge of ICl₂⁻
Formal charge = group no - ( no of non bonding electrons +no of bonds)
In I there are 7 electrons in outermost orbit . If we add one more electrons due to - ve charge on the ion , it becomes eight . This centrally placed iodine forms two single bond with two chlorine atoms on either side.
Each of chlorine atoms also contains 7 valance electrons like iodine.
So formal charge of chlorine
= group no - ( no of non bonding electrons +no of bonds)
= 7 - ( 6 + 1 )
= 0
So formal charge of iodine
= group no - ( no of non bonding electrons +no of bonds)
= 7 - ( 5 + 2 )
=0
Formal charge of ICl₂⁺
In this case , central iodine will have only 6 valence electrons due to absence one electron.
So formal charge of chlorine in ICl₂⁺
= group no - ( no of non bonding electrons +no of bonds)
= 7 - ( 6 + 1 )
= 0
formal charge of iodine in in ICl₂⁺
7 - ( 4 + 2)
= 1