Answer is: 6,16 kJ.
1) changing temperature of ice from -25°C to 0°C.
Q₁ = m·C·ΔT
Q₁ = 18 g · 2 J/g·°C · 25°C
Q₁ = 900 J.
m(H₂O) = 1mol · 18 g/mol = 18 g.
C - <span>specific heat of ice.
</span>2) changing temperature of water from 0°C to 70°C.
Q₁ = m·C·ΔT
Q₁ = 18 g · 4,18 J/g·°C · 70°C
Q₁ = 5266,8 J.
C - specific heat of water.
Q = Q₁ + Q₂ = 900 J + 5266,8 J
Q = 6166,8 J = 6,16 kJ.
It is a physical change because it is still the same thing (a pretzel) but just in two pieces. You’re not changing chemical composition.
Answer:
C
Explanation:
If the enthalpy change (i.e. Δ<em>H</em>) of a reaction is negative, then the reaction releases heat and is hence exothermic.
Hence, our answer is C.
Conversely, if Δ<em>H</em> is positive, the reaction absorbs heat and is endothermic.
Δ<em>H</em> tells us nothing about the speed of the reaction.
While Δ<em>H</em> influences free-energy change (Δ<em>G</em> = Δ<em>H</em> - <em>T</em>Δ<em>S</em>), we cannot predict the sign of Δ<em>G</em> given only Δ<em>H </em>(recall that a reaction is spontaneous if Δ<em>G</em> < 0).
Answer:
Use molar mass:)
Explanation:
3.62 mol of Sn (
)=429.694
Since 3.62 has 3 sig figs, limit 429.694 to 3
= 430
Answer by YourHope:
Hi! :)
Which definition of "coarse" matches its use in the phrase "coarse focus?"
A) "rough in texture"
Have a BEAUTIFUL day~
