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
Nitrogen (around 78%), Oxygen (around 21%), and Argon (around 1%).
Hope this helps :)
a) Copper is at a higher temperature, so the flow of heat will take place from copper to iron. Heat is a form of energy, which always flows from higher temperature to lower temperature.
b) To determine the actual final temperature, the heat capacity of the calorimeter must be known. A calorimeter constant refers to a constant, which quantifies the heat capacity of a calorimeter. It may be determined by using a known amount of heat to the calorimeter and measuring the corresponding change in temperature of the calorimeter.
Answer:
frogs, fish and aquatic (water-dwelling) insects
Explanation:
Answer:
167.980.
Explanation:
Hello!
In this case, since additions involving the display of the result with the appropriate number of significant figures involve the solution of the system without looking at them:
Considering that 156.325 is significant to the thousandths and 11.65498 to the hundred thousandths, we infer that the result should be taken to the thousandths as well as 156.325; thus, we obtain:
Because the second decimal nine is rounded to ten and therefore the 7 is taken to 8.
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