I'll mark like brainliest please

CO2+ NH3 --> H2NCONH2 + H2O

A).-How many moles of carbon dioxide are needed to react with 3.5 moles of ammonia?

B).-With 68.0 grams of ammonia, how many grams of urea is obtained.?

C).-With 8.0 moles of ammonia How many grams of water this reaction is obtained.?

A. 1.75mol of CO2

B. 120g of urea

C. 72g of water

Explanation:

The balanced equation for the reaction is given below:

CO2+ 2NH3 --> H2NCONH2 + H2O

A. From the balanced equation,

1mole of CO2 requires 2moles of NH3.

Therefore, Xmol of CO2 will require 3.5moles of NH3 ie

Xmol of CO2 = 3.5/2 = 1.75mol

B. Let us calculate their molar mass

MM of H2NCONH2 = (2x1)+14+12+16+14+(2x1) = 60g/mol

MM of NH3 = 14 +(3x1) = 17g/mol

But from the balanced equation, 2 moles of NH3 was required. Therefore the mass conc. of NH3 = 2 x 17 = 34g.

Now we calculate the mass of urea produced as follows:

From the equation,

34g of NH3 was required to produce 60g of urea.

Therefore, 68g of NH3 will produce Xg of urea i.e

Xg of urea = (68x60)/34 = 120g

C. From the balanced equation,

2moles of NH3 was required to produced 1mole of H2O.

Therefore, 8 moles of NH3 will produce Xmol of water ie

Xmol of H2O = 8/2 = 4moles

Converting this mole(4moles of water to grams), we have:

MM of H2O = (2x1)+ 16 = 18g/mol

Mass conc. of H20 = 4 x 18 = 72g

alchemy hadn't scientific methods of study, appeal to mysticism and fantasy, the knowledge of chemistry and physics were modest at that time.

alchemy was - but as new rules were discovered it either changed into chemistry or it became "unscientific".