This is an incomplete question, here is a complete question.
The conversion of cyclopropane to propene occurs with a first-order rate constant of 2.42 × 10⁻² hr⁻¹. How long will it take for the concentration of cyclopropane to decrease from an initial concentration 0.080 mol/L to 0.053 mol/L?
Answer : The time taken will be, 17.0 hr
Explanation :
Expression for rate law for first order kinetics is given by:

where,
k = rate constant = 
t = time passed by the sample = ?
a = initial concentration of the reactant = 0.080 M
a - x = concentration left = 0.053 M
Now put all the given values in above equation, we get


Therefore, the time taken will be, 17.0 hr
In prolonged fasting conditions acetyl-coa generated from the breakdown of amino acids and fatty acids does not enter the citric acid cycle in the liver, but acetyl-coa derived from ketone bodies can enter the citric acid cycle in the brain. <u>Cholesterol is required in the diet.</u>
<h3>What is
amino acids?</h3>
Amino acids are chemical molecules having side chains (R groups) unique to each amino acid as well as amino and carboxylic acid (CO2H) functional groups.
Every amino acid contains the elements carbon (C), hydrogen (H), oxygen (O), and nitrogen (N) (CHON); in addition, the side chains of cysteine and methionine contain sulfur (S), while the less frequent amino acid selenocysteine has selenium (Se). As of 2020, it is known that more than 500 naturally occurring amino acids make up the monomer units of peptides, including proteins.
Despite the fact that there are only 22 proteins, 20 of them have unique specified codons, and another two have unique coding mechanisms: All eukaryotes contain selenocysteine, and pyrrolysine is also present.
To learn more about amino acids from the given link:
brainly.com/question/21327676
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There are 3,500 milliseconds in 3.5 seconds. Hope this helps!
a) The reaction is exothermic since the overall enthalpy change is negative. this means that the system has lost energy to the environment, namely, the apparatus and due to drought.
b) We first calculate the number of moles in 3.55 grams of magnesium.
number of moles= mass/ atomic mass
=3.55/24
=0.1479 moles(to 4sf)
now, if 2 moles of magnesium give -1204kJ
How much energy is given by 0.1479 moles
= (0.1479×-1204kJ)
=-89.0358kJ (don't forget the negative sign)
c) two molesof MgO produces -1204kJ of energy
then -234kJ will be produced by
=(-234kJ×2moles)/1204kJ
=0.3887moles
one mole of MgO weighs 24+16=40
therefore the mass produced is 0.3887moles×40=15.548grams
(d) we first find the number of moles of MgO in 40.3 grams
number of moles=mass/RFM
=40.3g/40= 1.0075moles
if 2 moles of MgO give 1204 kJ then decomposing 1.0075 moles requires
(1.0075 moles×1204kJ)/2=606.515kJ