Answer:
52 da
Step-by-step explanation:
Whenever a question asks you, "How long to reach a certain concentration?" or something similar, you must use the appropriate integrated rate law expression.
The i<em>ntegrated rate law for a first-order reaction </em>is
ln([A₀]/[A] ) = kt
Data:
[A]₀ = 750 mg
[A] = 68 mg
t_ ½ = 15 da
Step 1. Calculate the value of the rate constant.
t_½ = ln2/k Multiply each side by k
kt_½ = ln2 Divide each side by t_½
k = ln2/t_½
= ln2/15
= 0.0462 da⁻¹
Step 2. Calculate the time
ln(750/68) = 0.0462t
ln11.0 = 0.0462t
2.40 = 0.0462t Divide each side by 0.0462
t = 52 da
Answer:
The initial temperature of the metal is 84.149 °C.
Explanation:
The heat lost by the metal will be equivalent to the heat gain by the water.
- (msΔT)metal = (msΔT)water
-32.5 grams × 0.365 J/g°C × ΔT = 105.3 grams × 4.18 J/g °C × (17.3 -15.4)°C
-ΔT = 836.29/12.51 °C
-ΔT = 66.89 °C
-(T final - T initial) = 66.89 °C
T initial = 66.89 °C + T final
T initial = 66.89 °C + 17.3 °C
T initial = 84.149 °C.
Answer:
increased
Explanation:
I believe to be increased ,because the coal is a natural resource to be used.
i really hope it helps
The correct matches are as follows:
<span>1.instantaneous combustion
</span>G.burning<span>
2.mass of substances before and after a reaction is the same
</span>C.Law of Conservation of Matter<span>
3.substances that combine
</span>A.reactants
<span>
4. Yields or makes
</span>B.arrow symbol
<span>
5.rapid oxidation
</span>F.explosion<span>
6.new substance
</span>D.product
<span>
7.slow oxidation
</span>E.rust
<span>
Hope this answers the question. Have a nice day.
</span>
