Answer:
<span>In the addition of hbr to 1-butyne the electrophile in the first step of the mechanism is <u>Hydrogen atom of HBr</u>.
Explanation:
In this reaction first of all HBr approaches the triple bond. A Pi Complex (weak inter-molecular interactions) is formed between the two molecules. And the triple bond attacks the partial positive hydrogen atom creating a negative charge on Bromine along with positive charge on itself (Sigma Complex). In second step the negative Bromide attacks the positive carbon of Butyne.</span>
A) H3PO4
H(+1),
P(X)
O(-2)
3*(+1)+x+4*(-2)=0, 3+x-8=0, x=+5
b)P2O5
P(x)
O(-2)
2x-2*5=0, 2x=10, x=+5
c) PH3
P(x)
H(+1)
x+3*(+1)=0, x+3=0, x=-3
Physical property- is an aspect of matter that can be observed or measured without touching changing it.
Chemical property- may only be observed by changing the chemical identity of a substance.
The difference would be that for physical property's you dont need to do anything to figure out what they are, but for chemical properties you need to change something to observe them.
