Answer : The correct option is, (b) 22.5 M
Explanation : Given,
Mass of calcium nitrate tetrahydrate = 266 g
Molar mass of calcium nitrate tetrahydrate = 236.15 g/mole
Volume of solution = 
Molarity : It is defined as the moles of solute present in one liter of solution.
Formula used :

Now put all the given values in this formula, we get:

As calcium nitrate tetrahydrate dissociate to give 1 mole of calcium ion, 2 moles of nitrate ion and 4 moles of water.
The concentration of nitrate ion = 
Thus, the concentration of nitrate ion is, 22.5 M
Answer:
B. They oxidize hydrocarbons to form less toxic gases.
Explanation:
A catalytic converter can be defined as an anti-pollution device containing a catalyst like platinum-iridium, installed in the exhaust chamber of an automobile so as to chemically convert harmful (poisonous) pollutants such as unburned hydrocarbons and carbon monoxide (CO), sulfur dioxide (S02), nitrogen oxide (NO) etc., into less harmful, poisonous or toxic chemical compounds.
This ultimately implies that, catalytic converters are typically used for converting harmful gases into less harmful, poisonous or toxic gases and molecules e.g carbon dioxide (C02) and water (H2O). This helps to prevent global warming, enhance the conservation of natural resources, as well as preserve the lives of living organisms and their natural habitat.
<em>Hence, the statement which best describes the use of catalytic converters in automobiles is that they oxidize hydrocarbons to form less toxic gases.</em>
Answer:
[H₃O⁺] = 3.162 × 10⁻⁹ moles / liter
Explanation:
The pH is calculated with the formula:
pH = -lg[H₃O⁺]
From here the concentration of hydronium ion (H₃O⁺) will be:
[H₃O⁺] = 
[H₃O⁺] = 
[H₃O⁺] = 3.162 × 10⁻⁹ moles / liter
Condensation is the change in state of matter from gas to liquid.
The gold leaf (not foil) is to give a sculpture or a painting appeal. Without it, it would discolour quicker.The gold leaf can be easily removed if needed to be.