Answer:
the specific heat of the unknown compound is 
Explanation:
Generally the change in temperature of water is evaluated as
Substituting 16.1°C for 
and 27.4°C for 
Generally the change in temperature of unknown compound is evaluated as
Substituting 27.4°C for and 94.3°C for 
Since there is an increase in temperature then heat is gained by water and this can be evaluated as
Substituting 179.1 g for m , 4.18 J/g.C for 
(specific heat of water)
Since there is a decrease in temperature then heat is lost by unknown compound and this can be evaluated as
By conservation of energy law
Heat lost = Heat gained
Substituting 306.9 g for 
, 8459.6J for 
Therefore 
Thus problem is providing us with the mass of iron (III) oxide as 12.4 g so the moles are required and found to be 0.0776 mol after the calculations:
<h3>Mole-mass relationships:</h3>
In chemistry, we use mole-mass relationships in order to calculate grams from moles and vice versa. In this case, since we are given the mass of iron (III) oxide as 12.4 g one can calculate the moles by firstly quantifying its molar mass:
Then, we prepare a conversion factor in order to cancel out the grams and thus, get moles:
Learn more about mole-mass relationships: brainly.com/question/18311376
Answer:
Q = 270 Joules (2 sig. figs. as based on temperature change.)
Explanation:
Heat Transfer Equation of pure condensed phase substance => Q = mcΔT
Mixed phase (s ⇄ l melting/freezing, or l ⇄ g boiling/condensation) heat transfer equation => Q = m∙ΔHₓ; ΔHₓ = phase transition constant
Since this is a pure condensed phase (or, single phase) form of lead (Pb°(s)) and not melting/freezing or boiling/condensation, one should use
Q = m·c·ΔT
m = mass of lead = 35.0g
c = specific heat of lead = 0.16J/g°C
ΔT = Temp change = 74°C - 25°C = 49°C
Q = (35.0g)(0.16J/g·°C )(49°C) = 274.4 Joules ≅ 270 Joules (2 sig. figs. as based on temperature change.)
C. It is decreased by a factor of 3.
