Answer:
100 Joule
Explanation:
Amount of heat in agiven body is given by Q = m•C•ΔT
where m is the mass of the body
c is the specific heat capacity of body. It is the amount of heat stored in 1 unit weight of body which raises raises the temperature of body by 1 unit of temperature.
ΔT is the change in the temperature of body
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coming back to problem
m = 5g
C = 2J/gC
since, it is given that temperature of body increases by 10 degrees, thus
ΔT = 10 degrees
Using the formula for heat as given
Q = m•C•ΔT
Q = 5* 2 * 10 Joule= 100 Joule
Thus, 100 joule heat must be added to a 5g substance with a specific heat of 2 J/gC to raise its temperature go up by 10 degrees.
First, balance the reaction:
_ KClO₃ ==> _ KCl + _ O₂
As is, there are 3 O's on the left and 2 O's on the right, so there needs to be a 2:3 ratio of KClO₃ to O₂. Then there are 2 K's and 2 Cl's among the reactants, so we have a 1:1 ratio of KClO₃ to KCl :
2 KClO₃ ==> 2 KCl + 3 O₂
Since we start with a known quantity of O₂, let's divide each coefficient by 3.
2/3 KClO₃ ==> 2/3 KCl + O₂
Next, look up the molar masses of each element involved:
• K: 39.0983 g/mol
• Cl: 35.453 g/mol
• O: 15.999 g/mol
Convert 10 g of O₂ to moles:
(10 g) / (31.998 g/mol) ≈ 0.31252 mol
The balanced reaction shows that we need 2/3 mol KClO₃ for every mole of O₂. So to produce 10 g of O₂, we need
(2/3 (mol KClO₃)/(mol O₂)) × (0.31252 mol O₂) ≈ 0.20835 mol KClO₃
KClO₃ has a total molar mass of about 122.549 g/mol. Then the reaction requires a mass of
(0.20835 mol) × (122.549 g/mol) ≈ 25.532 g
of KClO₃.
You can conclude that the solution is probably acidic because bases rarely react with metals.
