Chemical Engineering Archives

7841. For series reaction, the relative yield

Is always greater for plug-flow reactor than for the single CSTR of the same volume

Statement in A is wrong

Decreases with increasing conversion

Both A and C hold good

✅ The correct answer is option D.

7842. A rise in temperature

Normally tends to increase the reaction rate

Does not affect a catalysed reaction

Does not affect photo-chemical reaction rates

All of the above

✅ The correct answer is option D.

7843. Photochemical reaction rate does not depend significantly on temperature, because

It is a reversible reaction

It is an exothermic reaction

The energy of reacting molecules exceeds the activation energy by absorption of light

None of these

✅ The correct answer is option C.

7844. The rate of reaction of a/an __________ reaction is not affected by temperature rise.

Autocatalytic

Photochemical

Consecutive

Zero order

✅ The correct answer is option B.

7845. In autocatalytic reactions,

One of the reactants acts as a catalyst

One of the products acts as a catalyst

Catalysts have very high selectivity

No catalyst is used

✅ The correct answer is option B.

7846. The size of plug flow reactor (PFR) for all positive reaction orders and for any given duty, is __________ that of mixed reactor.

Greater than

Equal to

Smaller than

Unpredictable from the data

✅ The correct answer is option C.

7847. A catalyst in a chemical reaction

Decreases the activation energy

Alters the reaction mechanism

Increases the frequency of collisions of reacting species

All of the above

✅ The correct answer is option D.

7848. The effectiveness factor for large value of Thiele modulus (L√(K/D1)) of a solid catalysed first order reaction is equal to (where, L = length of the reactor, cm, D1 = diffusion co-efficient, cm²/second)

L√(K/D1)

1/(L√(K/D1))

∞

✅ The correct answer is option B.

7849. The concentration of A in a first order reaction, A → B, decreases

Linearly with time

Exponentially with time

Very abruptly towards the end of the reaction

Logarithmically with time

✅ The correct answer is option B.

7850. Consider the ‘n’ th order irreversible liquid phase reaction A → B. Which one of the following plots involving half life of the reaction (t1/2) and the initial reactant concentration (CA0) gives a straight line plot?

CA0 Vs t1/2

Ln CA0 Vs t1/2

CA0 Vs ln t1/2

Ln CA0 Vs ln t1/2

✅ The correct answer is option C.