<span>The gas phosphine (PH3) is used as a fumigant to protect stored grain and other durable produce from pests. Phosphine is generated where it is to be used by adding water to aluminum phosphide or magnesium phosphide. Give formulas for these two phosphides.
</span>Al₂P₃ + 3H₂O → 3PH₃ + Al₂O₃
MgP + H₂O → PH₃ + MgO
Answer:
Esterification reaction
Explanation:
When we have to go from an acid to an ester we can use the <u>esterification reaction</u>. On this reaction, an alcohol reacts with a carboxylic acid on acid medium to produce an ester and water. (See figure).
In this case, we need the <u>methyl ester</u>, therefore we have to choose the <u>appropriate alcohol</u>, so we have to use the <u>methanol</u> as reactive if we have to produce the methyl ester.
Answer: A solution will be hypertonic to a cell if its solute concentration is higher than that inside the cell, and the solutes cannot cross the membrane. If a cell is placed in a hypotonic solution, there will be a net flow of water into the cell, and the cell will gain volume.
Picture:
Meaning of hypertonic: (1): having a higher osmotic pressure than a particular fluid, typically a body fluid or intracellular fluid. (2) of or in a state of abnormally high muscle tone.
The half-life of any substance is the amount of time taken for half of the original quantity of the substance present to decay. The half-life of a radioactive substance is characteristic to itself, and it may be millions of years long or it may be just a few seconds.
In order to determine the half-life of a substance, we simply use:
t(1/2) = ln(2) / λ
Where λ is the decay constant for that specific isotope.
Answer:
Therefore it will take 7.66 hours for 80% of the lead decay.
Explanation:
The differential equation for decay is
Integrating both sides
ln A= kt+c₁
[]
The initial condition is A(0)= A₀,
.........(1)
Given that the has half life of 3.3 hours.
For half life putting this in equation (1)
[taking ln both sides, ]
⇒k= - 0.21
Now A₀= 1 gram, 80%=0.8
and A= (1-0.8)A₀ = (0.2×1) gram = 0.2 gram
Now putting the value of k,A and A₀in the equation (1)
⇒ t≈7.66
Therefore it will take 7.66 hours for 80% of the lead decay.