Answer:
The equilibrium temperature of the coffee is 72.4 °C
Explanation:
Step 1: Data given
Mass of cream = 15.0 grams
Temperature of the cream = 10.0°C
Mass of the coffee = 150.0 grams
Temperature of the coffee = 78.6 °C
C = respective specific heat of the substances( same as water) = 4.184 J/g°C
Step 2: Calculate the equilibrium temperature
m(cream)*C*(T2-T1) = -m(coffee)*c*(T2-T1)
15.0 g* 4.184 J/g°C *(T2 - 10.0°C) = -150.0g *4.184 J/g°C*(T2-78.6°C)
62.76T2 - 627.6 = -627.6T2 + 49329.36
690.36T2 = 49956.96
T2 = 72.4 °C
The equilibrium temperature of the coffee is 72.4 °C
If a mineral has a metallic shine and scratches, which of its properties are being measured?
Choose the two correct answers.
magnetism
hardness
cleavage
luster
Answer: hardness and luster
(B.Hallow bones because bones are inside the body
To solve for the enthalpy of reaction, we apply the Hess's Law.
ΔHrxn = ∑(ν×Hf of products) - ∑(ν×Hf of reactants)
where
v is the stoichiometric coefficient determined from the balanced reaction
Hf is the standard heat of formation; these are empirical values:
*For CH₄: Hf = <span>−74.87 kJ/mol
*For O</span>₂: Hf = 0
*For CO₂: <span>-393.5 kJ/mol
*For H</span>₂O: <span>-241.82 kJ/mol
</span>ΔHrxn = [(2*-241.82 kJ/mol)+(1*-393.5 kJ/mol)] - [(1*−74.87 kJ/mol)+(2*0 kJ/mol)] =<em> -802.27 kJ/mol</em>
Structurally, plant and animal cells<span> are very similar because they are both eukaryotic </span>cells<span>. They both contain membrane-bound organelles such as the nucleus, mitochondria, endoplasmic reticulum, golgi apparatus, lysosomes, and peroxisomes.</span>
