Molar mass of solute is 30 g/mol
molality is defined as the number of moles of solute in 1 kg of solvent
number of moles of solute - 5.0 g / 30 g/mol = 0.17 mol
molality of solution is 0.70 mol/kg
the mass of solvent when there are 0.7 mol of solute - 1 kg
then the mass of solvent when there's 0.17 mol of solute - 0.17 mol / 0.7 mol/kg
= 0.242 kg
therefore mass of solvent is 0.242 kg
Answer:What is used up in and stops a chemical reaction? (a) percent yield (b) limiting reactant (c) theoretical yield (d) excess reactant
The correct option is (b)
Explanation:
A chemical reaction is a chemical combination,rearrangement or disintegration of chemical substance(s) (called reactants) to form new chemical substance(s) (called products).
A limiting reactant is the reactant that is totally used up during the course of a reaction. When this reactant is used up, it limits the amount of products formed and eventually stops the chemical reaction.
Explanation:
The limiting reagent is the reactant that is used up completely. This stops the reaction and no further products are made. ... This method is most useful when there are only two reactants. The limiting reagent can also be derived by comparing the amount of products that can be formed from each reactant.
hope this helps have a nice day❤️
Answer:
C.) HOCl Ka=3.5x10^-8
Explanation:
In order to a construct a buffer of pH= 7.0 we need to find the pKa values of all the acids given below
we Know that
pKa= -log(Ka)
therefore
A) pKa of HClO2 = -log(1.2 x 10^-2)
=1.9208
B) similarly PKa of HF= -log(7.2 x 1 0^-4)= 2.7644
C) pKa of HOCl= -log(3.5 x 1 0^-8)= 7.45
D) pKa of HCN = -log(4 x 1 0^-10)= 9.3979
If we consider the Henderson- Hasselbalch equation for the calculation of the pH of the buffer solution
The weak acid for making the buffer must have a pKa value near to the desired pH of the weak acid.
So, near to value, pH=7.0. , the only option is HOCl whose pKa value is 7.45.
Hence, HOCl will be chosen for buffer construction.
Water has a chemical formula of H2O. This means that for every 2 moles of hydrogen and 1 mole of oxygen, one mole of water will be formed.
Note that hydrogen gas and oxygen gas are both biatomic molecules.
(1) (182 mol H2) x (1 mol H2O/ 1 mol H2) = 182 mol H2O
(2) (86 mol O2) x (2 mol H2O / 1 mol O2) = 172 mol H2O
We choose the smaller number of the two as the answer to this item. Thus, the answer to this question is 172 mol of H2O can be formed out of the given quantities.
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