Answer:
a
Explanation:
The correct statement about semi-empirical methods is
It combines a theoretically sound model of bonding with some experimentally determined parameters.
These methods are typically referred to by acronyms which encode some of the underlying theoretical assumptions.
Answer:
True
Explanation:
All irreversible reactions go to completion because the process cannot proceed in the backward direction.
A reversible reaction is one that does not go into completion in one direction.
An irreversible direction completely uses up the reactants to form the products and goes into completion.
These reactions can only proceed in one direction and not both.
Iron is a strong hard and tough metal, and it can resist the high load, stress and strain. Also, It's less brittle than stone yet, compared to wood or copper, extremely strong.
1) divide each percentage by the relative atomic mass of the element
2) divide all results by the smallest number
3)multiply by a whole number to get the simplest whole number ratio (if necessary)
that is to say:
Na S O
32.37÷23 22.58÷32 45.05÷16
= 1.407 = 0.7056 = 2.816 (to 4 significant figures)
the smallest number here is 0.7056 so:
1.407÷0.7056 0.7056÷0.7056 2.816÷0.7056
=1.99 approx.2 = 1 3.99 approx. 4
here there is no need to carry out step 3 as ratio obtained is already a simplest whole number ratio
so empirical formula is: Na₂SO₄