Some Basic Concepts of Chemistry · Chemistry · MHT CET

Calculate number of molecules present in 5.4 g of urea (Molar mass of urea $=60 \mathrm{~g} \mathrm{~mol}^{-1}$ )

Find out the total number of electrons present in 3.2 g methane?

Find the volume of 56 g dinitrogen at STP

Calculate percentage atom economy when 46 g ethanol is obtained from 64.5 g chloroethane and $56 \mathrm{~g} \mathrm{KOH}_{(\mathrm{aq})}$.

The vapour density of a certain gas is 16 . What is the volume occupied by 8 g of gas at STP assuming ideal behaviour?

Find out total number of electrons present in 1.6 g methane?

A gaseous mixture of $\mathrm{O}_2$ and $\mathrm{CH}_4$ are in the ratio $1: 4$ by mass. Find the ratio of their molecules.

Find the number of water molecules in 1 mL of water vapours at STP?

Calculate the number of $\mathrm{Cl}^{-}$ions in 222 g unhydrous calcium chloride?

(At. mass $\mathrm{Ca}=40, \mathrm{Cl}=35.5$ )

What is vapour density of $\mathrm{O}_2$ gas?

Calculate the number of $\mathrm{Ca}^{2+}$ ion in 222 g anhydrous calcium chloride? (At. Mass $\mathrm{Ca}=40, \mathrm{Cl}=35.5$ )

Find out number of carbon atoms present in 0.35 mole of glucose.

What is the mass in grams of 0.25 mol water?

If salicylic acid ( 138 u ) reacts with acetic anhydride ( 102 u ) to from aspirin ( 180 u ) calculate \% atom economy.

Find the mass of potassium chlorate required to liberate $5.6 \mathrm{dm}^3$ of oxygen gas at STP? (molar mass of $\mathrm{KClO}_3=122.5 \mathrm{~g} / \mathrm{mol}$ )

What is the molar mass of compound represented by following structure formula?

Calculate mass in kg of 2.5 mole ammonia.

Find the number of moles of sodium atoms in $6.9 \times 10^{-2} \mathrm{~kg}\left(\right.$ Atomic mass $\left.=23 \mathrm{~g} \mathrm{~mol}^{-1}\right)$

What is the percentage by mass of oxygen in NaOH ? (Atomic mass of $\mathrm{Na}=23 \mathrm{u}, \mathrm{O}=16 \mathrm{u}, \mathrm{H}=1 \mathrm{u}$ )

What is value of percent atom economy when reactants having sum of formula weight 78 u results in the formation of a product with formula weight 65 u ?

How many molecules of carbon dioxide are formed when 0.6 g carbon is burnt in air?

Which of the following pair of compounds cannot demonstrate law of multiple proportion?

What is the percentage atom economy when formula weight of product obtained is 70 u and the sum of formula weight of reactant is 140 u ?

Which law is illustrated by compounds $\mathrm{H}_2 \mathrm{O}$ and $\mathrm{H}_2 \mathrm{O}_2$ formed from two different elements, H and O ?

What is the volume of oxygen required for complete combustion of 0.25 mole of methane at S.T.P.?

Chlorine exists in two isotopic forms ${ }^{35} \mathrm{Cl},{ }^{37} \mathrm{Cl}$. If average atomic mass of chlorine is 35.5 , what is the percentage abundance of these isotopes respectively?

Chlorine has two isotopes ${ }^{35} \mathrm{Cl}$ and ${ }^{37} \mathrm{Cl}$ with average atomic mass of 35.5 . What is the ratio of their relative abundance respectively?

Calculate mass in kg of $4.48 \mathrm{dm}^3$ carbon dioxide at STP.

What is the volume occupied by 1 molecule of water, if its density is $1 \mathrm{~g} \mathrm{~cm}^{-3}$ ?

What is the number of moles of Cl atoms and N atoms respectively present in n moles of tear gas?

Calculate number of moles present in $9.10 \times 10^{-2} \mathrm{~kg}$ of water.

"A given compound always contains the same proportion of elements" is a statement of -

Which of the following pair of compounds does not demonstrate the law of multiple proportion?

What is the molar mass of third member of homologous series if the molar mass of first member is 46 g ?

How many moles of carbon atoms are present in 3.6 kg of carbon?

What is the mass in kg of 5 mole of acetic acid $\left(\mathrm{mol}\right.$. mass $\left.=60 \mathrm{~g} \mathrm{~mol}^{-1}\right)$ ?

Which of the following pair of compounds demonstrates the law of multiple proportions?

What is number of atoms present in $$2.24 \mathrm{~dm}^3 \mathrm{~NH}_{3(\mathrm{~g})}$$ at STP?

Calculate the percent atom economy when a product of formula weight $$175 \mathrm{u}$$ is obtained in a chemical reaction using $$225 \mathrm{u}$$ formula weight reactant.

According to reaction,

$$\mathrm{Mg}(s)+2 \mathrm{HCl}(a q) \longrightarrow \mathrm{MgCl}_2(a q)+\mathrm{H}_2(g) \uparrow .$$

Calculate the mass of $$\mathrm{Mg}$$ required to liberate $$4.48 \mathrm{~dm}^3 \mathrm{~H}_2$$ at STP?

(Molar mass of $$\mathrm{Mg}=24 \mathrm{~g} \mathrm{~mol}^{-1}$$)

What is the value of percent atom economy when an organic compound of formula weight $$75 \mathrm{~u}$$ is obtained from reactants having sum formula weight $$225 \mathrm{~u}$$ ?

Which from following substances consists of total 1 mole atoms in it? (Molar mass of $$\mathrm{NH}_3=17, \mathrm{H}_2 \mathrm{O}=18, \mathrm{~N}_2=28, \mathrm{CO}_2=44$$ )

How many moles of nitrogen atoms are present in $$8 \mathrm{~g}$$ of ammonium nitrate?

(Molar mass of ammonium nitrate $$=80$$ )

Calculate the $$\mathrm{pH}$$ of a buffer solution containing $$0.01 ~\mathrm{M}$$ salt and $$0.004 \mathrm{~M}$$ weak acid.

$$\left(\mathrm{pK}_{\mathrm{a}}=4.762\right)$$

What volume of ammonia is formed when $$10 ~\mathrm{dm}^3$$ dinitrogen reacts with $$30 ~\mathrm{dm}^3$$ dihydrogen at same temperature and pressure?

Identify number of moles of donor atoms in $$2 \mathrm{n}$$ mole of $$\mathrm{SCN}^{-}$$.

Which of the following concentration terms depends on temperature?

What is the mass in gram of 1 atom of an element if its atomic mass is $$10 ~\mathrm{u}$$ ?

How many gram of H$$_2$$O are present in 0.25 mol of it?

What is percentage atom economy during conversion of reactant to product if formula weight of reactants is 246 u and of product is 123 u?

Identify the change in colour when $$\mathrm{NaCl}$$ solution is titrated against $$\mathrm{AgNO}_3$$ solution using fluorescein indicator.

What is percent dissociation of acetic acid in it's $$0.01 \mathrm{~M}$$ solution if dissociation of acid is $$1.34 \times 10^{-2}$$ ?

How many molecules are present in $$22400 \mathrm{~cm}^3$$ of a gas at STP?

Calculate osmotic pressure exerted by a solution containing $$0.822 \mathrm{~g}$$ of solute in $$300 \mathrm{~mL}$$ of water at $$300 \mathrm{~K}$$.

(Molar mass of solute $$=340 \mathrm{~g} \mathrm{~mol}^{-1}, \mathrm{R}=0.0821 \mathrm{~L} \mathrm{~atm} \mathrm{~mol}^{-1} \mathrm{~K}^{-1}$$)

The pH of monoacidic weak base is 10.9. Calculate the percent dissociation in 0.02 M solution.

Lithium shows diagonal relationship with

How many molecules of ammonia gas are present in 67.2 dm$$^3$$, measured at S.T.P.?

What is the SI unit of density?

How many moles of urea are present in 5.4 g ? (Molar mass = 60)

What is the mass of potassium chloride produced when $$12.25 \mathrm{~g}$$ potassium chlorate undergo decomposition? (At mass: $$\mathrm{K}=39, \mathrm{Cl}=35.5, \mathrm{O}=16$$ )

Which from following formulae is a correct formula to determine percent atom economy?

What is the volume (in dm$$^3$$) occupied by 75 g ethane at S.T.P. ?

"Mass can neither be created nor destroyed" is the statement of

What amount of oxygen is used at S.T.P. to obtain 9 g water from sufficient amount of hydrogen gas?

What is value of percent atom economy if formula weight of product is 46 u and sum of formula weight of all reactants is 92 u?

$$60 \mathrm{~g} \mathrm{~CH}_3 \mathrm{COOH}$$ dissolved in $$1 \mathrm{~dm}^3$$ solvent, what is molality of solution?

(density = $$1.25 \mathrm{~g} / \mathrm{cm}^3$$)

What is the molarity of solution containing $$3.2 \mathrm{~g}$$ of $$\mathrm{NaOH}$$ (molar mass $$40 \mathrm{~g} \mathrm{~mol}^{-1}$$) in $$250 \mathrm{~cm}^3$$ of water?

The combining ratios of hydrogen and oxygen in water and hydrogen peroxide are $1: 8$ and $1: 16$. Which law is illustrated in this example?

What is the percentage of carbon in urea? (Atomic mass $C=12, H=1, N=14, O=16$)