Answer:
1.25 hours or 75 minutes or 1 hour and 15 minutes
Explanation:
Answer: A plot of the natural log of the concentration of the reactant as a function of time is linear.
Explanation:
Since it was explicitly stated in the question that the half life is independent of the initial concentration of the reactant then the third option must necessarily be false. Also, the plot of the natural logarithm of the concentration of reactant against time for a first order reaction is linear. In a first order reaction, the half life is independent of the initial concentration of the reactant. Hence the answer.
Answer:
The answer to the question is
The specific heat capacity of the alloy = 1.77 J/(g·°C)
Explanation:
To solve this, we list out the given variables thus
Mass of alloy = 45 g
Initial temperature of the alloy = 25 °C
Final temperature of the alloy = 37 °C
Heat absorbed by the alloy = 956 J
Thus we have
ΔH = m·c·(T₂ - T₁) where ΔH = heat absorbed by the alloy = 956 J, c = specific heat capacity of the alloy and T₁ = Initial temperature of the alloy = 25 °C , T₂ = Final temperature of the alloy = 37 °C and m = mass of the alloy = 45 g
∴ 956 J = 45 × C × (37 - 25) = 540 g·°C×c or
c = 956 J/(540 g·°C) = 1.77 J/(g·°C)
The specific heat capacity of the alloy is 1.77 J/(g·°C)
Freeze drying<span> (or lyophilization) removes water from the ice cream by lowering the </span>air pressure<span> to a point where ice sublimates from a </span>solid<span> to a </span>gas<span>. The ice cream is placed in a </span>vacuum chamber<span> and frozen until the water </span>crystallizes<span>. The air pressure is lowered, creating a partial vacuum, forcing air out of the chamber; next heat is applied, </span>sublimating<span> the ice; finally a freezing coil traps the vaporized water. This process continues for hours, resulting in a freeze-dried ice cream slice. </span>
