The choices can be found elsewhere and as follows:
a. mass-mass problems
<span>b. mass-volume problems </span>
<span>c. mass-particle problems </span>
<span>d. volume-volume problems
</span>
I believe the correct answer is option D. It is volume-volume problems that does not require the use of molar mass. <span> Here you are dealing with molarities and volumes to determine concentrations. Molar mass is not part of any calculations.</span>
This is a law because it describes the force but makes not attempt to explain how the force works. A theory is an explanation of a natural phenomenon. Einstein's General Theory of Relativity explains how gravity works by describing gravity as the effect of curvature of four dimensional spacetime.
Unburned hydrocarbon on reacting with oxygen undergoes combustion reaction. However, the activation energy of this reaction is significantly high. When a catalyst like Pd is added to the reaction system, it provides active sites for the reaction to occur. It acts are a heterogeneous catalyst. It is pertinent of note that catalyst is refereed as heterogeneous, when it exist in different phase as compared to reactant and products. In present case, reactants and products are in gas phase, while catalyst is in solid phase. Due to availability of larger surface area at active site of Pd, activation energy of reaction decreases and decrease in activation energy favors higher reaction rates.