Answer:
Explanation: 1 gram is equal to 1000 Milligrams so
Since you go straight across its just multiplication so 0.00200x1000=200mg
To answer it in scientific notation it should just be mg
CxHy + O2 --> x CO2 + y/2 H2O
Find the moles of CO2 : 18.9g / 44 g/mol = .430 mol CO2 = .430 mol of C in compound
Find the moles of H2O: 5.79g / 18 g/mol = .322 mol H2O = .166 mol of H in compound
Find the mass of C and H in the compound:
.430mol x 12 = 5.16 g C
.166mol x 1g = .166g H
When you add these up they indicate a mass of 5.33 g for the compound, not 5.80g as you stated in the problem.
Therefore it is likely that either the mass of the CO2 or the mass of H20 produced is incorrect (most likely a typo).
In any event, to find the formula, you would take the moles of C and H and convert to a whole number ratio (this is usually done by dividing both of them by the smaller value).
The reaction is a double displacement one which means the cation of one reactant is substituted to the cation of the other reactant to identify the products. Hence in this reaction, the products are silver ammonium nitrate (Ag(NH3)2NO3) and hydrochloric acid (HCl).