Base your answer to the question on the information below and on your knowledge of chemistry. At 1023 K and 1 atm, a 3.00-gram s
ample of SnO2(s) (gram formula mass = 151 g/mol) reacts with hydrogen gas to produce tin and water, as shown in the balanced equation below. SnO2(s) + 2H2(g) → Sn(L) + 2H2O(g) Show a numerical setup for calculating the number of moles of SnO2(s) in the 3.00-gram sample.
To calculate for the number of moles of SnO2 in the sample, we need the value of the products from the reaction. Since we do not have that data, we can assume that all of the sample is SnO2. Then, we are given the molecular mass of the sample, 151g/mol.
So, the number of moles is 3g / 151 g/mol = 0.0199 moles SnO2
There was an improvement in accuracy. There was no change in precision.
Explanation:
<em>The average mass after recalibration is closer to the mass of the standard, </em>so the recalibration improved the accuracy<em> </em>(the measurement is closer to an accepted 'true' value).
The standard deviation did not change, so the precision (or how disperse the measurements are) was not affected.
The answer is (3) moles of solute per liter of solution. That is what the definition of molarity of a solution means. The equation is concentration = mol number of solute/ volume of solution.
