Answer:
Its b its the state not anything else
D=m/v. (Density equals mass over volume).
So in your case density = 4.2/6
Which equals 0.7
Your units will be grams over milliliters
So your answer is 0.7 g/ml
The answer is Make sure you are working with a properly balanced chemical equation.
Convert grams of the substance given in the problem to moles.
Construct two ratios - one from the problem and one from the chemical equation and set them equal. ...
Convert moles of the substance just solved for into grams. Step 1: Convert known reactant mass to moles. ...
Step 2: Use the mole ratio to find moles of other reactant. ...
Step 3: Convert moles of other reactant to mass. Balance the equation.
Convert units of a given substance to moles.
Using the mole ratio, calculate the moles of substance yielded by the reaction.
Convert moles of wanted substance to desired units.
<h3>
Answer</h3>
HF
<h3>Explanation</h3>
A buffer solution contains <em>a weak acid</em> and<em> its conjugate base</em>. The two species shall have a similar concentration in the solution. It's also possible for <em>a weak base</em> and <em>its conjugate acid</em> to form a buffer solution.
The KF solution already contains large number of 
ions. The objective is to thus find its conjugate acid or base.
contains no proton 
and is unlikely to be a conjugate acid. Assuming that is a conjugate base. Adding one proton to would produce its conjugate acid.
Therefore 
is the conjugate acid of . happens to be a weak acid. As a result, combining with would produce a solution with large number of both the weak acid and its conjugate base, which is a buffer solution by definition.
