Your answer is B, conservation of mass
Recall that percent yield is given by: %Yeild = actual yeild/theoretical yeild x100
During experiments, there are errors made:
• uncertainty in measurements
• losses of reactants and products
• impurity in reactants
• losses during separation (e.g. filtration or purification)
• Some side reactions might also happen.
Among the given options, only conservation of mass does not contribute to a lower actual yield compared to the theoretical yield.
The equation is
W = C/F
W= 3.00 x 10^8 m/sec
——————————
6.165 x 10^14 Hz
W= 4.87 x 10^-7 m
Energy is
E=hF
E= (6.626 x 10^-34 Jxsec )(6.165 x 10^14 Hz)
E= 4.085 x 10^-19 J
<h2>Hey There!</h2><h2>_____________________________________</h2><h2>Answer:</h2>

<h2>_____________________________________</h2><h2>CALORIMETER:</h2>
Calorimeter is device used for the measurement of heat. In a calorimeter we can use the temperature change of water to quantify an amount of heat. A calorimeter just captures all the energy released (or absorbed) by a reaction in the water. So Option A and B are wrong as calorimeter don't have anything to do with providing the heat or letting the the heat in, as it is the insulated calorimeter too.
<h2>_____________________________________</h2><h2>Energy in the reaction:</h2>
In the formation of any bond there is equal amount of heat required as to break that bond. It means Energy released in the making of bond is equal to the energy required in the breaking of the bond. So Option D is wrong as it says we need more energy in making then breaking.
<h2>_____________________________________</h2><h2>Enthalpy:</h2>
Enthalpy is the total heat content of the system. As we provide energy to the reactants and the product is formed, so The enthalpy(heat content) of product is more than the Enthalpy of the reactant, Thus Option C is correct.
Enthalpy is denoted by H or Q, its formula is,
H = U + PV
Where,
U is internal energy
PV is equals to Work done ; P = Pressure, V = Volume
<h2>_____________________________________</h2><h2>Best Regards,</h2><h2>'Borz'</h2><h2> </h2>
Answer: You can probably go onto <em><u>You Tube and find that answer!</u></em> Just be <u><em>detailed in your search!</em></u> Hope this helps!
Explanation:
Just Simple Physics :P