Answer:
A molecule is tetrahedral if the central atom has four bonds and no lone pairs.
Explanation:
A typical example is a molecule of methane (see image).
The electron pairs in the bonds repel the electrons in the other bonds, so they all try to get as far from each other as possible.
They can do this if the bonds point to the corners of a tetrahedron, with bond angles of 109.5°.
Answer:
The concentration of KBr is 
Explanation:
From the question we are told that
The mass of KBr is 
The molar mass of KBr is 
Volume of water is 
This implies that the volume of the solution is 
The number of moles of KBr is
Substituting values
The concentration of KBr is mathematically represented as
Imagine a chemist is in the lab and trying to make some chemical reactions happen. In one reaction she reacts chemicals in an exothermic reaction and there is an increase in entropy. A second chemical reaction she is trying to run is endothermic and there is a decrease in entropy. Which of the two reactions is more likely to occur and why?
A mole is a unit to describe an amount of something/specific substance. Typically standard for measuring a large quantity of small entities like atoms, molecules, or other particles.
