Answer: 20.7 kJ
Explanation:
According to first law of thermodynamics:
=Change in internal energy
q = heat absorbed or released
w = work done or by the system
w = work done on the system=
{Work is done on the system is positive as the final volume is lesser than initial volume}
w = 4.51 kcal = 
(1kcal = 4.184kJ)
q = +1.79 kJ {Heat absorbed by the system is positive}
Thus for a system that receives 1.79 kJ of heat from surroundings and has 4.51 kcal of work done on it at the same time is 20.7 kJ
Ans: Elements in the same period have the same number of electron shells.
Balance the equation first:
2 KClO3 (s) ---> 2 KCl (s) + 3 O2 (g)
Moles of KClO3 = 110 / 122.5 = 0.89
Following the balanced chemical equation:
We can say moles of O2 produce =
x moles of KClO3
So, O2 = (3 / 2) x 0.89
= 1.34 moles
So, Volume at STP = nRT / P
T = <span>273.15 K
P = 1 atm
So, V = (1.34 x 0.0821 x 273.15) / 1 = 30.2 L</span>
Answer:
0.0432M
Explanation:
We begin by writing a balanced equation for the reaction. This is illustrated below:
NaOH + HCl —> NaCl + H2O
From the equation above,
The number of mole of the acid (nA) = 1
The number of mole of the base (nB) = 1
Data obtained from the question include:
Vb (volume of the base) = 54mL
Cb (concentration of the base) = 0.1M
Va (volume of the acid) = 125mL
Ca ( concentration of the acid) =?
Using CaVa/CbVb = nA/nB, the concentration of the acid can easily be obtained as shown below:
CaVa/CbVb = nA/nB
Ca x 125 / 0.1 x 54 = 1
Cross multiply to express in linear form:
Ca x 125 = 0.1 x 54
Divide both side by 125
Ca = (0.1 x 54) / 125
Ca = 0.0432M
Therefore, the concentration of the acid is 0.0432M
It is <span>a substance produced by a living organism that acts as a catalyst to bring about a specific biochemical reaction.
So I think C matches the discription </span>
