Answer:
7 moles
Explanation:
The molecular formula of sodium sulfide is Na_2S
One molecule of Sodium sulfide has 2 atoms of sodium and one atom of sulfur
1 mole of Sodium sulfide has 2 moles of sodium and one mole of sulfur
so 3.5 moles of sodium sulfide will have 2× 3.5 moles of sodium atoms
i.e 2×3.5= 7 moles of sodium atom
Answer:
1. 67.2 kJ/mol
Explanation:
Using the derived expression from Arrhenius Equation

Given that:
time
= 8.3 days = (8.3 × 24 ) hours = 199.2 hours
time
= 10.6 hours
Temperature
= 0° C = (0+273 )K = 273 K
Temperature
= 30° C = (30+ 273) = 303 K
Rate = 8.314 J / mol
Since 
Then we can rewrite the above expression as:








In all chemical equations, regardless of the type of reaction that is occurring, the reagents that are on the left side of the arrow are the reactants and on the right your products.
B. Is the solution.
By definitions of the prefixes in the metric system, the prefix milli- (abbreviated as m as in mg) indicates 1/1000 or 1 x 10^-3 of a gram. In this case, if a beaker has a mass of 77.275 g (I am assuming this is grams since most other units would make it too heavy or too light), we would multiply this by 1000 to convert it to milligrams. So 77.275 g = 77,275 mg.