19 What is the number of moles of nitrogen gas which react with 18 g of magnesium to form magnesium nitride compound ? [Mg = 24,N=14] a) 0.25 mol 0 b) 0.5 mol C) 1 mol d) 2 mol

0.5 mol of nitrogen gas.

Explanation:

18g of Magnesium in mol is equal to 18g/24 gmol-1 = 0.75 mol and 7g of nitrogen in mol is equal to 7g/14 gmol-1 = 0.5 mol,

Thus, When 18g of magnesium reacts with 7g of nitrogen it implies 0.75 mol of magnesium which reacts with 0.5 mol of nitrogen. :)

answer: they produce more slow than unicellular organisms.

answer : third trial had the contaminated sample and the correct value for dhrxn should be 1000 kj/mol

explanation :

let us write down the given equations

equation 1 :

equation 2 :

equation 3 :

let us use hess's law to find out which 2 equations can be added to get the third equation.

let us reverse equation 2 and multiply it by 2. the new equation that we get is,

equation 4 :

let us add equation 1 & 4

the above equation is similar to equation 3 but has different value for dhrxn.

therefore third trial had the contaminated sample and the correct value for dhrxn should be 1000 kj/mol