The statement which best describes the law of conservation of mass is A) when a physical or a chemical change occurs, matter is not created or destroyed. The law states that matter cannot be created or destroyed by ordinary chemical or physical changes, which means that <span>the mass of all the components of a chemical reaction can be measured before and after the change in order prove that the mass is constant. So, keep in mind that </span><span>the mass of participating products is always the same as the mass of all the reactants.</span>
Answer : The volume of 6M NaOH stock solution is, 16.7 mL
Explanation :
To calculate the volume of NaOH stock solution, we use the equation given by neutralization reaction:

where,
are the molarity and volume of NaOH stock solution.
are the molarity and volume of NaOH.
We are given:

Putting values in above equation, we get:

Thus, the volume of 6M NaOH stock solution is, 16.7 mL
It is.
An acid will be strong when its conjugated base is highly stable, and vice-versa.
That can occur for instance through electronic delocalization.
First find the oxidation states of the various atoms:
<span>in Cr2O2 2- Cr @ +1; In NH3 N @ +3; in CrO3 Cr @ +3, N2 N @ 0 </span>
<span>Note that N gained electrons, ie, was reduced; Cr was oxidized </span>
<span>Now there is a problem, because B has NH4+ which the problem did not, and is not balanced, showing e- in/out </span>
<span>B.NH4+ → N2 </span>
<span>Which of the following is an oxidation half-reaction? </span>
<span>A.Sn 2+ →Sn 4+ + 2e- </span>
<span>Sn lost electrons so it got oxidized</span>