# Chemical Reaction Engineering homework

• herbertpbarreto
In summary, the decomposition of phosphine at 953 K in a constant-volume batch reactor is a first-order reaction with a rate constant of 0.0155 s-1. For 40% conversion of PH3, the time required is 32.96 s and the mole fraction of H2 in the reaction mixture is 0.6.
herbertpbarreto

## Homework Statement

The decomposition of phosphine 4PH3(g) + P4(g) + 6H2(g) is first-order with respect to phosphine with a rate constant k = 0.0155 s-l at 953 K. If the decomposition occurs in a constant-volume batch reactor at 953 K, calculate, for 40% conversion of PH3,

(a) the time required, s;
(b) the mole fraction of H2 in the reaction mixture.

(
-rA)=-dCa/dT
(-rA)=kCa
Ca= Ca0 (1-Xa)

## The Attempt at a Solution

a) i attempet do apply the equation for spatial time I am batch reactors:
-dCa/dT = kCa
∫-dCa/Ca =∫kdT
-ln(Ca/Ca0) = kT
-ln (Ca0(1-Xa)/Ca0) = kT
-ln (1-Xa) = kT --> -ln (1-0,4) = 0,0155 * T --> -ln(0,6)/0,0155 =T
T = 32,96 s
b) i have no idea

Last edited:
herbertpbarreto said:

## Homework Statement

The decomposition of phosphine 4PH3(g) + P4(g) + 6H2(g) is first-order with respect to phosphine with a rate constant k = 0.0155 s-l at 953 K. If the decomposition occurs in a constant-volume batch reactor at 953 K, calculate, for 40% conversion of PH3,

(a) the time required, s;
(b) the mole fraction of H2 in the reaction mixture.

b) i have no idea

So of the total original molecules of PH3 0.6 of them are still PH3, and of the 0.4 that have reacted each one has become 1.5 molecules of H2 and ¼ of P4 according to your formula (which should have a → instead of a + ) and you have any difficulty in finding what fraction H2 molecules are of the total?

herbertpbarreto

## What is Chemical Reaction Engineering?

Chemical Reaction Engineering is a branch of engineering that deals with the design and optimization of chemical reactions in order to produce desired products. It involves the study of kinetics, thermodynamics, and transport phenomena in chemical systems.

## What are the main types of chemical reactions?

The main types of chemical reactions are combustion, synthesis, decomposition, single displacement, double displacement, acid-base, and redox reactions. Each type involves the transfer or exchange of energy, atoms, or ions between reactants to form products.

## How do you determine the rate of a chemical reaction?

The rate of a chemical reaction can be determined by measuring the change in concentration of reactants or products over time. This can be done experimentally by collecting data at different time intervals and plotting a graph, or mathematically using reaction rate equations derived from reaction kinetics.

## What factors influence the rate of a chemical reaction?

The rate of a chemical reaction is influenced by several factors including temperature, concentration of reactants, surface area or particle size, presence of catalysts, and pressure (for gaseous reactions). These factors affect the frequency of collisions and the energy of collisions between reactant molecules, which ultimately determine the reaction rate.

## How is Chemical Reaction Engineering used in real-world applications?

Chemical Reaction Engineering has numerous real-world applications, such as in the production of fuels, pharmaceuticals, and consumer products. It is also used in environmental engineering to design processes for waste treatment and pollution control. Additionally, it plays a crucial role in the development of new materials and technologies, such as batteries and renewable energy sources.

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