The heat of combustion of propane, c3h8, is 2220 kj/mol. the specific heat of water is 4.184 j/g·°c. mrs. s lives in the country and uses propane to heat things. how many litresof propane at stp must be burned to raise the temperature of 1.00 l of water from 20.0°c to 100.0°c so that mrs. s can make herself a nice cup of tea? assume that no heat is lost to the surroundings and remember that the density of water is 1.00 g/ml. and if propane costs 88.9 cents per litre, how much did the propane cost to heat the water?

(a) 3.38 Litres  (b)  $3‬.00

Explanation:

Q=Quantity of Heat required to make  the cup of tea

Q = mcΔФ

   m = mass of water      

    c=  Specific capacity of water, 4.184 J/g/° C

    p = density of water, 1g/mL

    v =  volume of water for tea, v= 1L or 1000mL

    ΔФ= Change in Temperature , T₂ -T₁, T₂= 100°C,  T₁=20°C

m = 1 g/mL x 1000 mL

   =  1000g

Q= 1000 x 4.184 (100-20)

  = 1000 x 4.184 x 80

  = 334,720‬J

Number of moles of propane required =  Q/ heat of combustion

                                                               =  334,720‬/ 2220000

                                                                = 0.150774 moles

At STP, 1 mole of every gas occupies 22.4 dm³

0.150774 moles of propane will occupy = 0.150774 x  22.4

                                                                  =  3.3773376 ‬dm³

                                                                   = 3.3773376 Litres

                                                                   ≈ 3.38 Litres

If the cost per litre of propane is 88.9cent or $0.889

The total cost of propane for the tea will be =  0.889 x  3.38

                                                                         = $3.00482

                                                                         ≈ $3‬

explanation:

the largest database of organic compounds lists about 10 million substances, which include compounds originating from living organisms and those synthesized by chemists. the number of potential organic compounds has been estimated at 1060—an astronomically high number. the existence of so many organic molecules is a consequence of the ability of carbon atoms to form up to four strong bonds to other carbon atoms, resulting in chains and rings of many different sizes, shapes, and complexities. the simplest organic compounds contain only the elements carbon and hydrogen, and are called hydrocarbons. even though they are composed of only two types of atoms, there is a wide variety of hydrocarbons because they may consist of varying lengths of chains, branched chains, and rings of carbon atoms, or combinations of these structures. in addition, hydrocarbons may differ in the types of carbon-carbon bonds present in their molecules. many hydrocarbons are found in plants, animals, and their fossils; other hydrocarbons have been prepared in the laboratory. we use hydrocarbons every day, mainly as fuels, such as natural gas, acetylene, propane, butane, and the principal components of gasoline, diesel fuel, and heating oil. the familiar plastics polyethylene, polypropylene, and polystyrene are also hydrocarbons. we can distinguish several types of hydrocarbons by differences in the bonding between carbon atoms. this leads to differences in geometries and in the hybridization of the carbon orbitals.