20. the following is a limiting reactant problem: magnesium nitride is formed in the reaction of magnesium metal with nitrogen gas in this reaction: 3 mg(s) + n2(g) --> mg3n2(s) how many grams of product are formed from 2.0 mol of n2 (g) and 8.0 mol of mg(s)? show all calculations leading to an answer.

201.90 grams.

Based on the equation:

Only 2.0 moles of Mg₃N₂ will be produced in the end. The reaction will run out of N₂ (g) before all Mg (s) is consumed. N₂ (g) is the limiting reactant. As a result, the quantity of N₂ (g) supplied determines the quantity of Mg₃N₂ produced.

Refer to a periodic table for relative atomic mass values. Mg₃N₂ has a molar mass of 3 × 24.31 + 2 × 14.01 = 100.95 g/mol. As a result, the 2.0 mol of Mg₃N₂ produced will have a mass of 2 × 100.95 = 201.90 grams.

Answers:

2.0 × 10² g Mg₃N₂

Step-by-step explanation:

We are given the masses of two reactants, so this is a limiting reactant problem.

We know that we will need moles and molar masses, so, lets assemble all the data in one place, with molar masses above the formulas and masses below them.

M_r:                          100.93  

           3Mg + N₂ ⟶ Mg₃N₂

n/mol:  8.0    2.0

Step 1. Identify the limiting reactant

Calculate the moles of Mg₃N₂ we can obtain from each reactant.

From Mg:  

The molar ratio of Mg₃N₂:Mg is 1:3

Moles of Mg₃N₂ = 8.0 × 1/3  

Moles of Mg₃N₂ = 2.67 mol Mg₃N₂

From N₂:

The molar ratio of Mg₃N₂: N₂ is 1:1.  

Moles of Mg₃N₂ = 2.0 × 1/1  

Moles of Mg₃N₂ = 2.00 mol Mg₃N₂  

N₂ is the limiting reactant because it gives the smaller amount of Mg₃N₂.  

Step 2. Calculate the theoretical yield.

Theor. yield = 2.00 mol Mg₃N₂ × 100.93 g Mg₃N₂/1 mol Mg₃N₂

Theor. yield = 2.0 × 10² g Mg₃N₂

i know insulin is primary but i dont know the others im sorry

explanation:

pre-sliced bread is a relatively recent development in baking technology. previous to that, it was always sold in a bakery in daily-made contiguous loaves with no wrapping, and was moderately perishable, usually being used with a day or two (which is why every bakery had a discounted “day-old” bread table.) therefore, pre-sliced bread would grow stale quickly. the hard crust provided a protective layer, and once the exposed dry slice left from the previous cut was removed, the interior was still soft.

what keeps bread soft is the moisture retained in the crumb (the light spongy part that’s not crust). the reason the crust develops is the surface of the dough gets exposed to hot dry air during baking which browns the outer layer and seals it, preventing all the moisture from escaping the dough. longer exposure to air will also eventually cause your bread to lose flavor and become stale.

people were used to cutting slices as they needed them and storing bread in a specially-made wooden or metal breadbox or pail with a lid to preserve it longer, but the first automatically sliced commercial loaves were produced on july 6, 1928, in chillicothe, missouri, using a machine invented by otto rohwedder, an iowa-born, missouri-based jeweler.[1] pre-sliced bread would indeed dry out, were it not for another 20th century technology: the plastic bag. bread could now be pre-sliced, and if the enclosing bag remains sealed as much as possible, the bread will remain soft and fresh for longer than if sitting unwrapped on a shelf or enclosed in a bread box that is not air-tight. sealed packaging meant bread could also be sold on store shelves and eliminate frequent trips to a bakery.

sealing bread in a plastic bag had another effect: the moisture in the loaf will re-distribute into the crust and soften it, which is sometimes more pleasing in a sandwich - especially for children whose teeth might not yet be strong enough to tear through a hard crust. a homemade loaf of bread can be sealed in a bag overnight and the crust will become soft like store-bought sandwich bread.

these were novel changes in how bread was produced and sold, which led to the coining of the phrase “the greatest thing since sliced bread.”