PO4 anion has a 3- charge.A sodium cation , has a 1+ charge.Now , you have to think how many Na ions you need to fully neutralize the PO4 's 3- charge. Answer 3. That's because a molecule must have a neutral charge (a 0 charge). 3+(-3)=0.So , sodium phosphate has the formula Na3PO4.
Answer:

Explanation:
At
, the heat of vaporization of water is given by:

The water here condenses and gives off heat given by the product between its mass and the heat of vaporization:

The block of aluminum absorbs heat given by the product of its specific heat capacity, mass and the change in temperature:

According to the law of energy conservation, the heat lost is equal to the heat gained:
or:

Rearrange for the final temperature:

We obtain:

Then:

A covalent bond, also called a molecular bond, is a chemical bond that involves the sharing of electron pairs between atoms
Answer:
It has direction and size.
Explanation:
All physical quantities are generally grouped into two;
i) Vector quantities
ii) Scalar quantities
Vector quantities are those quantities that has both magnitude (size) and direction.
Scalar quantities are those quantities that has magnitude (size) and no direction.
Velocity is a vector quantity because it has direction and size.
<h3><u>Answer;</u></h3>
A) HNO3 and NO3^-
<h3><u>Explanation;</u></h3>
- <em><u>HNO3 is a strong acid and NO3 is its conjugate base, meaning it will not have any tendency to withdraw H+ from solution.</u></em>
- Buffers are often prepared by mixing a weak acid or base with a salt of that weak acid or base.
- The buffers resist changes in pH since they contain acids to neutralize OH- and a base to neutralize H+. Acid and base can not consume each other in neutralization reaction.