GATE-CH-0100-1-pc-1mark

How many grams of oxygen are in 65.0 g of C₂H₂O₂? (Atomic weights: C - 12, H - 1; O - 16)

• 18
• 29
• 9.5
• 35.9

GATE-CH-0100-2-pc-1mark

A nitrogen oxide is 30.4% by mass nitrogen. The molecular formula could be ______ (Atomic weight of N is 14 and that of O is 16).

• NO
• N₂O₄
• either NO₂ or N₂O₄
• NO₂

GATE-CH-0100-3-pc-1mark

For a steady state system

• The rate of input is zero
• The rate of generation is zero
• The rate of consumption is zero
• The rate of accumulation is zero

GATE-CH-1995-2-g-pc-2mark

Assuming that \(\ce {CO2}\) obeys perfect gas law, calculate the density of \(\ce {CO2}\) (in kg/m\(^3\)) at 0\(^\circ \)C and 2 atm.

• 1

• 2

• 3

• 4

GATE-CH-1998-2-7-pc-2mark

A sample of well water contains 140 g/m\(^{3}\) \(\ce {Ca^{2+}}\) ions and 345 g/m\(^{3}\) \(\ce {Na^{+}}\) ions. The hardness of the sample of water, expressed in terms of equivalent \(\ce {CaCO3}\) in g/m\(^3\) [assuming atomic masses of Ca = 40, Na = 23, C = 12 and O = 16] is

• 350

• 485

• 140

• 345

GATE-CH-2000-1-7-pc-1mark

The molar composition of a gas is 10% H₂, 10% O₂, 30% CO₂ and balance H₂O. If 50% H₂O condenses, the final mole percent of H₂ in the dry gas will be

• 10%
• 5%
• 18.18%
• 20%

GATE-CH-2004-6-pc-1mark

The weight fraction of methanol in an aqueous solution is 0.64. The mole fraction of methanol \( x_M \) satisfies

• \( x_M < 0.5 \)
• \( x_M = 0.5 \)
• \( 0.5 < x_M < 0.64 \)
• \( x_M \ge 0.64 \)

GATE-CH-2005-5-pc-1mark

A process flow sheet analysis results in the degrees of freedom having a value of -2. Which one of the following steps must be next carried out?

• Identify and add two new independent equations from process model
• Remove two equations that have been wrongly assumed to be independent
• Assign values to two variables in the process
• Assign value to one variable and remove one equation that was wrongly assumed to be independent

GATE-XE-2014-E-3-pc-1mark

The molecular weight of a mixture is 38.4 g/mol. The mixture is composed of methane and carbon-dioxide gases. The atomic weights of the elements C, H, and O are 12, 1, and 16 g/mol, respectively. The mole fraction of methane ( \(X_{\text{methane}} \) ) is ________ and that of carbon-dioxide (\( X_{\text{carbon-dioxide}} \) ) is _______. 

• \( X_{\text{methane}}=0.2; X_{\text{carbon-dioxide}} = 0.8 \)

• \( X_{\text{methane}}=0.8; X_{\text{carbon-dioxide}} = 0.2 \)

• \( X_{\text{methane}}=0.3; X_{\text{carbon-dioxide}} = 0.7 \)

• \( X_{\text{methane}}=0.7; X_{\text{carbon-dioxide}} = 0.3 \)