Answer:
Step-by-step explanation:
Remark
The formula for this is
Heat = m * c * Δt
Givens
Heat = unknown
m = 200 grams
c = 4.184 Joules / grams oC
Δt = the change in temperature = 35.7 - 22.3 = 13.4
Solution
Heat = 200 * 4.184 * 13.4
Heat = 11213 Joules
Heat = 11.2 Kj
It's hard to get the correct number of sig digs because the 200 is not qualified in any way.
Part 2.
This can really puzzle you until you know that heat given up = the heat taken on. The heat taken on was 11.2 Kj. The Butane lighter must have given that heat on.
Heat of Combustion = Heat Given Up / Number grams burned.
Heat of Combustion = 11.2 Kj / 0.23 grams
Heat of Combustion = 48.8 Kj / gram
Answer:
375
Step-by-step explanation:
12½[30] → 25⁄2[30]
Multiply 25 by 30 [750] then divide by 2 to get 375.
I am joyous to assist you anytime.
The third one :) I hope I did it right
x² - x - 12 ≠ 0
x² - 4x + 3x - 12 ≠ 0
x (x - 4) + 3 (x - 4) ≠ 0
(x + 3)(x - 4) ≠ 0
x ≠ -3 or x ≠ 4
(B)
Today: x=19
y=67+19=86
9 years ago: x=19-9=10
y=86-9=77
The total age 9 years ago: x+y=10+77=87
