GATE MT 2019 Paper 1 — page 18

Questions 52–54 of 65. Imported answers require review unless explicitly marked reviewed.

A 50 mm (diameter) sphere of solid nickel is oxidized in a gas mixture containing 60% argon and 40% oxygen by volume. The rate of oxidation of nickel is controlled by the rate of transport of oxygen through the concentration boundary layer. The rate of oxidation (in moles of nickel per minute (mol/min), rounded off to two decimal places) is ________.

Given: Total pressure = 1 atm, Temperature = 1173 K; Concentration of oxygen at the surface of the solid = 0; Boundary layer mass transfer coefficient = 0.03

; Universal gas constant,

= 8.205

. Assume ideal gas behavior.

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

Equilibrium concentration of dissolved nitrogen (in wt.%, rounded off to three decimal places) in pure liquid iron, exposed to atmospheric air at 1873 K, is ________.

Given: Sieverts’ law constant as a function of temperature (

; in Kelvin) is

where

has the dimension of

. Assume

, where

is the activity of nitrogen with respect to 1 wt.% Henrian standard state.

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

Pressure drop in the granular zone of a blast furnace is 300 mm of water per meter of the bed height. The bed permeability is 0.8

. The volumetric flow rate of gas per unit area through the bed [in

, rounded off to the nearest integer] is ________.

Assume Darcy’s law is applicable and

. Density of water = 1000

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

2019 · Paper 1

Question 42

Question 43

Question 44