<span>The half-life of a first-order reaction is determined as follows:
</span>t½<span>=ln2/k
From the equation, we can calculate the </span><span>first-order rate constant:
</span>k = (ln(2)) / t½ = 0.693 / 90 = 7.7 × 10⁻³
When we know the value of k we can then calculate concentration with the equation:
A₀ = 2 g/100 mL
t = 2.5 h = 150min
A = A₀ × e^(-kt) =2 × e^(-7.7 × 10⁻³ × 150) = 0.63 g / 100ml
= 6.3 × 10⁻⁴ mg / 100ml
Hey there!:
From the given data ;
Reaction volume = 1 mL , enzyme content = 10 ug ( 5 ug in 2 mg/mL )
Enzyme mol Wt = 45,000 , therefore [E]t is 10 ug/mL , this need to be express as "M" So:
[E]t in molar = g/L * mol/g
[E]t = 0.01 g/L * 1 / 45,000
[E]t = 2.22*10⁻⁷
Vmax = 0.758 umole/min/ per mL
= 758 mmole/L/min
=758000 mole/L/min => 758000 M
Therefore :
Kcat = Vmax/ [E]t
Kcat = 758000 / 2.2*10⁻⁷ M
Kcat = 3.41441 *10¹² / min
Kcat = 3.41441*10¹² / 60 per sec
Kcat = 5.7*10¹⁰ s⁻¹
Hence kcat of xyzase is 5.7*10¹⁰ s⁻¹
Hope that helps!
Answer:
The mass of Mg consumed is 21.42g
Explanation:
The reaction is
As per balanced equation, three moles of Mg will react with one mole of nitrogen to give one mole of magnesium nitride.
as given that mass of nitrogen reacted = 8.33g
So moles of nitrogen reacted = 
moles of Mg required = 3 X moles of nitrogen taken = 3X0.2975 = 0.8925mol
Mass of Mg required = moles X molar mass = 0.8925 X 24 = 21.42 g
Answer:
The adjustable legs and the table of sand.
<em>Note:The question is incomplete. The complete question is given below.</em>
Using Models to Answer Questions About Systems
Armando’s class was looking at images of rivers formed by flowing water. Most of the rivers were wide and shallow, but one river was narrow and deep. Armando’s class thinks that this river is narrow and deep because:
- the hill that the water flowed down was very steep, or
- the sand grains that the water flowed through were very small.
Armando designed the model below to try to answer the question: Why is this river so narrow and deep?
Explanation:
The model designed by Armando will be helpful to answer the question because of the following features it possesses:
1. An adjustable leg- since one of the hypotheses put forward by the class to explain why the river was narrow and deep was that the hill that the water flowed down was very steep, the adjustable legs can be lowered or raised in order to make the slope shallower or steeper so that their hypothesis can be tested.
2. A table of sand- the table of sand serves as the streambed. By adjusting the size of the sand grains to be larger or smaller, the students will be able to to test their second hypothesis that the small size sand grains that the water flowed through was the reason for the river to be narrow and deep.
The results of their experiments will enable them to come to a conclusion.
Answer:
The number on the lag label should be 15.
Explanation:
It seems your question is incomplete, as it is lacking the working values. An internet search showed me the full question, you can see it in the attached picture.
Let's say we have 100 g of the fertilizer.
- <em>45 g are of ammonium phosphate</em> ( (NH₄)₃PO₄ ), of which:
- 45 g (NH₄)₃PO₄ *
= 12.7 g are of Nitrogen.
(We used the molar mass of ammonium phosphate in the denominator and three times the molar mass of nitrogen in the numerator)
- <em>18 g are of calcium nitrate</em> (Ca(NO₃)₂), of which:
- 16 g Ca(NO₃)₂ *
= 2.73 g are of Nitrogen.
So in total there are (12.7+2.73) 15.43 g of Nitrogen in 100 g of the fertilizer. So the percent by mass of nitrogen is 15.43%.
Rounding to the nearest percent the answer is 15.
