C. air, fire, water, earth. 4 elements
I'm not sure what you mean. Besides, I feel like you're talking math.
But anyways, if you have 120 let's say
The scientific notation is 1.20 × 10^2
if you have 125000
the scientific notation is 1.25 × 10^ 5
The number of times you go left the decimal, I guess exponent increases
So yea
Answer:
1384 kJ/mol
Explanation:
The heat absorbed by the calorimeter is equal to the heat released due to the combustion of the organic compound. C is the total heat capacity of the calorimeter and Δt is the change in temperature from intial to final:
Q = CΔt = (3576 J°C⁻¹)(30.589°C - 25.000°C) = 19986.264 J
Extra significant figures are kept to avoid round-off errors.
We then calculate the moles of the organic compound:
(0.6654 g)(mol/46.07) = 0.0144432 mol
We then calculate the heat released per mole and convert to the proper units. (The conversion between kJ and J is infinitely precise and is not involved in the consideration of significant figures)
(19986.264 J)(1kJ/1000J) / (0.0144432 mol) = 1384 kJ/mol
Molarity is defined as the number of moles of solute in 1 L of solution
molarity of solution to be prepared is 0.85 M
this means that there should be 0.85 mol of KBr in 1 L of solution
if 1 L contains - 0.85 mol
then 25.0 mL should contain - 0.85 mol / 1000 mL x 25.0 mL = 0.0213 mol
mass of KBr - 0.0213 mol x 119 g/mol = 2.53 g
mass of KBr that should be dissolved in 25.0 mL is 2.53 g
