General Q&A for Class 12 · Page 188
5,215 free answers in General for Class 12 students, across CBSE, ICSE and State boards.
Question & Answer
Questions
- GeneralClass 12All
What organ does ethanol damage?
The liver is the primary organ damaged by ethanol, as it's responsible for metabolizing alcohol. Chronic consumption causes fatty liver, hepatitis, fibrosis, and cirrhosis. Ethanol also damages the brain (causing cognitive impairment), heart (cardiomyopathy), pancreas (pancreatitis), and digestive system.
- GeneralClass 12All
Can smelling ethanol harm you?
Brief exposure to ethanol vapors typically isn't harmful, though it may cause eye, nose, and throat irritation. Prolonged inhalation in poorly ventilated areas can lead to headaches, dizziness, and respiratory irritation. In industrial settings with high concentrations, vapor exposure can be more dangerous and requires proper ventilation.
- GeneralClass 12All
Why can we digest ethanol but not methanol?
The human body can metabolize both, but with very different results. Ethanol is processed by the enzyme alcohol dehydrogenase into acetaldehyde, then acetic acid (like vinegar), which is relatively harmless. Methanol is processed into formaldehyde and formic acid, both highly toxic compounds that damage the optic nerve and vital organs. Interestingly, ethanol can be used as an antidote for methanol poisoning because it competes for the same enzyme.
- GeneralClass 12All
Which is drinkable, ethanol or methanol?
Only ethanol is drinkable. Methanol is extremely poisonous and should never be consumed. Unfortunately, illegal or counterfeit alcoholic beverages sometimes contain methanol, leading to severe poisoning or death.
- GeneralClass 12All
Is ethanol drinkable alcohol?
Yes, ethanol is the only type of alcohol safe for human consumption and is the active ingredient in all alcoholic beverages. However, this refers to beverage-grade ethanol—industrial or denatured ethanol contains additives that make it undrinkable and toxic.
- GeneralClass 12All
Why do humans need ammonia?
The human body produces small amounts of ammonia naturally during protein metabolism and amino acid breakdown. However, ammonia is toxic to the body, so the liver quickly converts it into urea, which is safely excreted through urine. We don't "need" external ammonia—our bodies produce what's necessary internally.
- GeneralClass 12All
Why do fish smell of ammonia?
Fresh fish shouldn't smell strongly of ammonia. The ammonia odor develops as fish spoils bacteria break down proteins and other nitrogen-containing compounds, releasing ammonia. A strong ammonia smell indicates the fish is old and should not be eaten. Fresh fish has a mild, ocean-like smell, not a pungent ammonia odor.
- GeneralClass 12All
What is a safe level of ammonia in drinking water?
The EPA doesn't set a maximum contaminant level for ammonia in drinking water, but levels above 0.5 mg/L (parts per million) can affect taste and odor. Water treatment facilities typically maintain ammonia below 0.2 mg/L. Higher concentrations may indicate contamination from agricultural runoff or sewage and should be investigated.
- GeneralClass 12All
Is ammonia in food harmful?
Food-grade ammonia compounds used in processing are generally safe when used within regulated limits. The amounts are tiny, and ammonia typically evaporates during cooking or processing. However, consuming high concentrations of ammonia would be harmful. Properly processed foods containing approved ammonia compounds pose no significant health risk.
- GeneralClass 12All
Is ammonia gas toxic?
Yes, ammonia gas is toxic, especially at high concentrations. While low levels cause eye, nose, and throat irritation, exposure to concentrated ammonia can cause severe respiratory damage, chemical burns, and even death. Concentrations above 300 parts per million are considered immediately dangerous to life and health.
- GeneralClass 12All
What is the cleanest type of fuel?
Hydrogen is often considered the cleanest fuel as it produces only water when burned. However, ammonia is emerging as a carbon-free fuel alternative that's easier to store and transport than hydrogen. When combusted, ammonia produces nitrogen and water without carbon emissions, though nitrogen oxides require management. The "cleanest" designation depends on production methods and application.
- GeneralClass 12All
Can you run an engine on ammonia?
Yes, engines can run on ammonia fuel, and this technology is being developed for shipping, power generation, and potentially vehicles. Ammonia combustion produces no carbon dioxide, making it attractive for decarbonization. However, engines require modifications to handle ammonia's different combustion characteristics, and nitrogen oxide emissions must be controlled.
- GeneralClass 12All
What are the dangers of ammonia?
Ammonia poses several hazards including respiratory irritation, chemical burns to skin and eyes, and potential lung damage from inhalation. Mixing ammonia with bleach creates toxic chloramine gas. At high concentrations, it can cause blindness, permanent lung damage, or be fatal. Always use ammonia in well-ventilated areas and wear protective equipment when handling concentrated forms.
- GeneralClass 12All
Is ammonia eco-friendly?
Ammonia has both positive and negative environmental aspects. As a fertilizer, it helps feed billions but runoff causes water pollution and algal blooms. As a potential fuel, it produces no carbon dioxide when burned, only nitrogen and water, making it attractive for reducing emissions. However, production via the Haber-Bosch process currently requires significant energy and releases CO₂.
- GeneralClass 12All
Is baking soda the same as ammonia?
No, baking soda (sodium bicarbonate, NaHCO₃) and ammonia (NH₃) are completely different chemical compounds. While both are alkaline and used for cleaning, they have different chemical structures, properties, and applications. Baking soda is much milder and safer to handle than ammonia.
- GeneralClass 12All
What happens if you mix vinegar with ammonia?
No, baking soda (sodium bicarbonate, NaHCO₃) and ammonia (NH₃) are completely different chemical compounds. While both are alkaline and used for cleaning, they have different chemical structures, properties, and applications. Baking soda is much milder and safer to handle than ammonia.
- GeneralClass 12All
How long will ammonia last outside?
When released outdoors, gaseous ammonia disperses relatively quickly due to air movement and reacts with moisture in the atmosphere. In liquid form on surfaces, it typically evaporates within minutes to a few hours depending on temperature, humidity, and ventilation. Ammonia doesn't persist long in the environment as it readily dissolves in water or reacts with other compounds.
- GeneralClass 12All
Can I mix ammonia and baking soda?
Yes, ammonia and baking soda can be safely mixed and are sometimes combined in cleaning solutions. This combination creates an effective cleaner for tough stains and grease. However, never add bleach to any ammonia mixture, as this creates dangerous toxic gases.
- GeneralClass 12All
What are the uses of ammonia?
Ammonia has diverse applications including fertilizer production (its largest use, accounting for about 80% of production), refrigeration systems, household and industrial cleaning products, water treatment, pharmaceutical manufacturing, and as a feedstock for producing plastics, explosives, and synthetic fibers. It's also being explored as a carbon-free fuel.
- GeneralClass 12All
What is the medical use of ammonia?
Medically, ammonia inhalants (smelling salts) containing ammonium carbonate are used to revive people from fainting by stimulating breathing reflexes. Historically, they've been used to treat shock and loss of consciousness. However, this use has declined with better understanding of the risks associated with ammonia exposure.