Butane (c4h10) is the liquid fuel in lighters. how many grams of carbon are present within a lighter containing 7.25 ml of butane? (the density of liquid butane is 0.601 g/ml.) express the mass in grams to three significant figures.

Density is calculated using the following rule:
density = mass / volume

We have the volume of butane = 7.25 ml and the density of butane = 0.601 g/ml
mass of butane = volume x density = 7.25 x 0.601 = 4.35725 grams

From the periodic table:
mass of carbon = 12 grams and mass of hydrogen = 1 gram
mass of C4H10 = 4(12) + 10(1) = 58 grams
Therefore, each 58 grams of butane contains 48 grams of carbon.
To know the mass of carbon in 4.35725 grams of butane, we will simply do cross multiplication as follows:
mass of carbon = (4.35725 x 48) / 58 = 3.606 grams

Answer : option c) heat is released during the process.explanation :

the enthalpy of formation of water is given as -285.8kj/mol, which states that the enthalpy of formation is negative.

negative enthalpy of formation indicates that the heat is released during the reaction process. the heat is released from reaction to the surroundings the enthalpy is expressed with a negative sign with the energy given out in the reaction process.

the formation of water takes place by giving out heat which is -285.8 kj/mol.