Cheat Sheet: Hydrogen | Chemistry for JEE Main & Advanced PDF Download

 Page 1


Hydrogen Cheat Sheet 
Position in Periodic Table 
Feature Hydrogen Alkali Metals Halogens 
Position 1st element, Z=1, 
1s¹ 
Group 1 (ns¹) Group 17 (ns²np 5) 
Behavior Lose/gain 1 e ? Lose 1 e ? (M ?) Gain 1 e ? (X ?) 
Properties Reducing agent, 
forms halides (HCl), 
diatomic (H 2) 
Reducing agent, 
halides (NaCl) 
Electronegative, 
diatomic (Cl 2), halides 
Placement Separate (dual 
nature) 
Group 1 Group 17 
Occurrence & Isotopes 
? O c c u r r e n c e: 70% universe, 0.15% Earth atmosphere, 15.4% in 
water/crust. 
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Hydrogen Cheat Sheet 
Position in Periodic Table 
Feature Hydrogen Alkali Metals Halogens 
Position 1st element, Z=1, 
1s¹ 
Group 1 (ns¹) Group 17 (ns²np 5) 
Behavior Lose/gain 1 e ? Lose 1 e ? (M ?) Gain 1 e ? (X ?) 
Properties Reducing agent, 
forms halides (HCl), 
diatomic (H 2) 
Reducing agent, 
halides (NaCl) 
Electronegative, 
diatomic (Cl 2), halides 
Placement Separate (dual 
nature) 
Group 1 Group 17 
Occurrence & Isotopes 
? O c c u r r e n c e: 70% universe, 0.15% Earth atmosphere, 15.4% in 
water/crust. 
Isotope Symbol Protons/Neutrons Abundance Applications 
Protium ¹H 1/0 99.98% Fuel cells, 
ammonia, 
hydrogenation 
Deuterium ²H (D) 1/1 0.015% Heavy water, 
NMR, nuclear 
fusion 
Tritium ³H (T) 1/2 10 ?¹ 8% Nuclear 
weapons, 
self-powered 
lighting 
Properties 
Type Property Details 
Physical Density 0.089 kg/m³ (gas), 70.79 kg/m³ (liquid) 
Boiling Point -252.76°C 
Melting Point -259.16°C 
State Gas (H 2, diatomic), colorless, odorless 
Page 3


Hydrogen Cheat Sheet 
Position in Periodic Table 
Feature Hydrogen Alkali Metals Halogens 
Position 1st element, Z=1, 
1s¹ 
Group 1 (ns¹) Group 17 (ns²np 5) 
Behavior Lose/gain 1 e ? Lose 1 e ? (M ?) Gain 1 e ? (X ?) 
Properties Reducing agent, 
forms halides (HCl), 
diatomic (H 2) 
Reducing agent, 
halides (NaCl) 
Electronegative, 
diatomic (Cl 2), halides 
Placement Separate (dual 
nature) 
Group 1 Group 17 
Occurrence & Isotopes 
? O c c u r r e n c e: 70% universe, 0.15% Earth atmosphere, 15.4% in 
water/crust. 
Isotope Symbol Protons/Neutrons Abundance Applications 
Protium ¹H 1/0 99.98% Fuel cells, 
ammonia, 
hydrogenation 
Deuterium ²H (D) 1/1 0.015% Heavy water, 
NMR, nuclear 
fusion 
Tritium ³H (T) 1/2 10 ?¹ 8% Nuclear 
weapons, 
self-powered 
lighting 
Properties 
Type Property Details 
Physical Density 0.089 kg/m³ (gas), 70.79 kg/m³ (liquid) 
Boiling Point -252.76°C 
Melting Point -259.16°C 
State Gas (H 2, diatomic), colorless, odorless 
Type Property Details 
Other Low solubility, high compressibility, thermal 
conductivity 
Chemical Combustion 2H 2 + O2 ? 2H 2O 
Halogens H2 + X 2 ? 2HX (X = F, Cl, Br, I) 
Nitrogen 3H 2 + N2 ? 2NH3 (873 K, 200 atm) 
Hydrides Metallic (NaH), covalent (CH 4, NH 3) 
Reducing Agent Reduces metal oxides, forms H ? in acids 
Uses 
Category Use 
Industry Haber process (NH 3), hydrogenation (fats, oils), methanol 
production 
Energy Fuel cells, rocket fuel, nuclear fusion (deuterium, tritium) 
Page 4


Hydrogen Cheat Sheet 
Position in Periodic Table 
Feature Hydrogen Alkali Metals Halogens 
Position 1st element, Z=1, 
1s¹ 
Group 1 (ns¹) Group 17 (ns²np 5) 
Behavior Lose/gain 1 e ? Lose 1 e ? (M ?) Gain 1 e ? (X ?) 
Properties Reducing agent, 
forms halides (HCl), 
diatomic (H 2) 
Reducing agent, 
halides (NaCl) 
Electronegative, 
diatomic (Cl 2), halides 
Placement Separate (dual 
nature) 
Group 1 Group 17 
Occurrence & Isotopes 
? O c c u r r e n c e: 70% universe, 0.15% Earth atmosphere, 15.4% in 
water/crust. 
Isotope Symbol Protons/Neutrons Abundance Applications 
Protium ¹H 1/0 99.98% Fuel cells, 
ammonia, 
hydrogenation 
Deuterium ²H (D) 1/1 0.015% Heavy water, 
NMR, nuclear 
fusion 
Tritium ³H (T) 1/2 10 ?¹ 8% Nuclear 
weapons, 
self-powered 
lighting 
Properties 
Type Property Details 
Physical Density 0.089 kg/m³ (gas), 70.79 kg/m³ (liquid) 
Boiling Point -252.76°C 
Melting Point -259.16°C 
State Gas (H 2, diatomic), colorless, odorless 
Type Property Details 
Other Low solubility, high compressibility, thermal 
conductivity 
Chemical Combustion 2H 2 + O2 ? 2H 2O 
Halogens H2 + X 2 ? 2HX (X = F, Cl, Br, I) 
Nitrogen 3H 2 + N2 ? 2NH3 (873 K, 200 atm) 
Hydrides Metallic (NaH), covalent (CH 4, NH 3) 
Reducing Agent Reduces metal oxides, forms H ? in acids 
Uses 
Category Use 
Industry Haber process (NH 3), hydrogenation (fats, oils), methanol 
production 
Energy Fuel cells, rocket fuel, nuclear fusion (deuterium, tritium) 
Category Use 
Chemistry HCl production, ore reduction, vanaspati fat 
Other Welding, balloons, NMR (deuterium), lighting (tritium) 
Tips for Solving 
? P o s i t i o n: H resembles alkali metals (lose e ?) and halogens (gain 
e ?). 
? I s o t o p e s: Check neutrons: ¹H (0), ²H (1), ³H (2). 
? P r o p e r t i e s: Memorize key reactions (H 2 + O 2, H 2 + X 2, H 2 + N 2). 
Solved Examples 
Example 1: Identify isotopes with 1 proton, 2 neutrons. 
Protons=1, neutrons=2 ? ³H (Tritium). 
Ans: Tritium. 
 
Example 2: Why does H resemble halogens? 
Both gain 1 e ? (H ?, Cl ?), diatomic, non-metallic, form halides. 
Ans: Gains 1 e ?, diatomic, non-metallic. 
 
Example 3: Reaction of H 2 with Cl 2. 
H 2(g) + Cl 2(g) ? 2HCl(g). 
Ans: 2HCl.