The reaction between potassium chlorate and red phosphorus takes place when you strike a match on a matchbox. If you were to react 52.9 g of potassium chlorate (KCIO 3 ) with excess red phosphorus, what mass of tetraphosphorus decaoxide (P 4 O 10 ) could be produced? KClO 3 ( s ) + P 4 ( s ) � P 4 O 10 ( s ) + KCl ( s ) ( unbalanced )

Interpretation: The mass of tetraphosphorus decaoxide produced by the given chemical process is to be calculated.

Concept introduction: The mass of a substance can be obtained by using the number of moles of the substance present and its molar mass. The formula used to calculate the mass of a given substance is,

Mass of the substance=(Number of moles)×(Molar mass of the substance)

To determine: The amount of tetraphosphorus decaoxide produced by the stated chemical process.

To determine: A balanced form of the given chemical equation.

The stated reaction is,

KClO3(s)+P4(s)→P4O10(s)+KCl(s)

According to the law of conservation of mass, mass can neither be created nor destroyed. The mass of reactants is equal to the mass of products formed. Therefore a chemical equation, having lesser number of moles of an element on either side of a reaction, is balanced using appropriate numerical coefficients to satisfy the law of conservation of mass.

Adding the coefficient 10 to KClO3 and the coefficient 3 to P4O10 balances the number of atoms of oxygen present on either side of the reaction. The equation thus obtained is,

10KClO3(s)+P4(s)→3P4O10(s)+KCl(s)

Adding the coefficient 3 to P4 and the coefficient 10 to KCl balances the number of atoms of potassium, chlorine and phosphorus present on either side of the reaction. The balanced equation thus obtained is,

10KClO3(s)+3P4(s)→3P4O10(s)+10KCl(s)

Hence, the balanced chemical equation is,

10KClO3(s)+3P4(s)→3P4O10(s)+10KCl(s) .

To determine: The amount of tetraphosphorus decaoxide produced by the stated chemical process.

The chemical reaction involved is,

10KClO3(s)+3P4(s)→3P4O10(s)+10KCl(s)

The mass of potassium chlorate is 52.9 g .

Molar mass of potassium chlorate (KClO3) =K+Cl+3O=(39+35.5+(3×16)) g/mol=122.5 g/mol

Formula

The number of moles of a substance is calculated by the formula,

Number of moles=Given mass of the substanceAtomic mass of the substance

Substitute the value of the given mass and the atomic mass of potassium chlorate in the above expression