1) In order to write formulas of chemical compounds we need the periodic table to find out some oxidation numbers.
Sulfuric acid: H2SO4. This compound has a polyatomic ion called sulfate with a 2- charge. To balance those negative charges we need two H+ ions.
Nitrogen: N2
Oxygen: O2
Ammonia: NH3
Lime: CaCO3. This compound is made up of calcium (Ca2+) and a polyatomic ion called carbonate (CO3 2-). Two positive charges and two negative charges. It is balanced.
Phosphoric acid: H3PO4. This compound has a polyatomic ion called phosphate with a 3- charge. In this compound, we need 3 H+ to balance those negative charges.
Sodium hydroxide: NaOH. Hydroxide compounds have a two-part name. The name of the cation (Na+) and the name of the hydroxide (OH-). One positive charge and one negative charge. It is balanced.
Chlorine: Cl2.
Sodium carbonate: Na2CO3. This compound has a polyatomic ion called carbonate with a 2- charge. We need two positive charges to balance the compound. Sodium is in the first group in the periodic table. That means sodium has just one positive charge, so we need two sodiums.
Nitric acid: HNO3. This compound has a polyatomic ion called nitrate with a 1- charge. To balance that negative charge we need one H+ ion.
One of the activity of laboratory is the addition of acid to water.
The addition of acid to water make it easier for the reaction so that the acid gets diluted safely. On the other hand if water is added to acid it will get splash vigrously and may injure the hand of the chemist. The addition of water directly to acid contribute to exothermic reaction and releases more heat which may result in spraying around.
Adding acid to water, result in solution with very dilute solution and releases small heat. This small heat is not sufficient even to vaporizes a single drop of water.
Thus, adding acid to water is safer for dilution.
Answer:
"True"
Explanation:
Breathing released by humans is naturally acidic. When humans inhale, there are also dangerous toxic substances such as carbon dioxide in the lungs inside the human body, which are neutralized with the help of HCl hydrochloric acid, but due to hydrochloric acid, the breath that man leaves becomes acidic.
<span>Physical properties are any properties of matter which can be perceived or observed without changing the chemical identity of the sample.</span>
