Introduction to Fundamental Concepts of Chemistry

Sulphur has oxidation state of:

Which material possesses the highest pH?

Which is the best drying agent in desiccators?

The mobile phase in paper chromatography is usually:

Osmotic pressure of a solution is _ property.

The process of filtration is used to separate particles _ from liquids.

_ extraction is controlled by partition law.

36 g of HCl dissolves in 100 g of solution. The density of HCl is 1.19 gcm^-3. The molar mass of the HCl solution will be:

Paper chromatography is used for:

The acid which can be purified by the sublimation is:

A limiting reactant is the one which:

Seawater has 5.65 x 10^-3 g of dissolved oxygen in one kilogram of water. Concentration of O₂ in parts per million is

The purity of a substance can be identified by:

Sublimation is used to purify:

If we are given the mass of one substance, we can calculate volume of other substances and vice a versa with the help of balanced chemical equation. This is called:

Molarity is defined as the number of moles of any substance dissolved:

Mole fraction of any compound is the ratio of moles of all components in a:

How many 'Cl' (chlorine) molecules are in two moles of chlorine?

In MgCl₂, the oxidation state of ‘Cl’ is :

When 8 grams (4 moles) of H₂ react with 2 moles of O₂ , how many moles of water will be formed?

Hydrogen burns in chlorine to produce hydrogen chloride. The ratio of masses of reactants in the chemical reaction is:H₂ + Cl₂ → 2HCl

In SO₄^-2 the oxidation number of Sulphur is:

The number of molecules in 9 g of ice (H₂O) is:

Given solution contains 16.0 g of CH₃OH, 92.0 g of C₂H₅OH and 36 g of water. Which statement about mole fraction of the components is true?

10.0 grams of glucose are dissolved in water to make 100 cm³ of its solution, its molarity is:

How many moles of sodium are present in 0.1 g of sodium?

What mass of NaOH is present in 0.5 mol of sodium hydroxide?

The number of moles of CO₂ that contain 8g of oxygen is:

Which of the following has the same number of molecules as there are in 11g of CO₂?

There are almost 200 million people alive in Pakistan. If you were to distribute 100 to each Pakistani in the form of 5 Rupee coins, how many moles of coins are you required to have?

In NO₃^- the oxidation number of N is:

Choose the correct option regarding number or particles associated with one mole of a substance:

Calculate the grams of H₂O formed when 8g of CH₄ burns in excess of oxygen:

Determine the number of moles of O in 10.6g of Na₂CO₃:

While finding the relative atomic mass, which of the following standard is used to compare the atomic mass of chlorine (35.5 amu):

3.0 mole of Calcium will contain _ g of Calcium.

The formula which shows the simplest whole number ratio for the atoms of different elements in a compound is:

Solution contains 85.5g of sucrose (C₁₂H₂₂O₁₁) in 250 cm³. What is its molarity?

The number of moles of water in 1 kg ice are:

How many moles of Calcium Carbonate are present in 1.75 kg of Calcium Carbonate? (Ar of Ca = 40, Ar of C = 12, Ar of O = 16)

During stoichiometric calculations, which of the following laws must be followed?

In which of the following, oxygen shows fractional oxidation number?

A compound of sodium oxide has 74.2% of sodium and 25.8% of Oxygen. The empirical formula of the compound is?

0xidation number of free magnesium is?

A compound of phosphorus oxide has 43.6% of Oxygen. Its empirical formula is?

The number of moles in an element is directly proportional to:

Consider the given balanced chemical equation: 2H₂​+O₂​→2H₂​O

If 4 g of H₂ reacts with 32 g of O₂ to produce 28 g of H₂O, what is the percentage yield of the reaction?

(Molar mass of H₂ = 2 g/mol, O₂ = 32 g/mol, and H₂O = 18 g/mol)

Oxidation numbers of X, Y Z are +6, -2, & -1 respectively, possible molecular formula when atoms combine:

If % yield and actual yield is 80 and 20 g respectively, what will be theoretical yield?

A chemical reaction has a theoretical yield of 25g, but only 20g of product was obtained. What is the percentage yield of the reaction?

Consider the equation H₂ + O₂H₂O, what volume of hydrogen gas is required to produce 1 mol of water at standard temperature & pressure?

For the reaction, FeS₂ + KMnO₄ + H⁺→ Fe³⁺ + H₂SO₄ + Mn²⁺ + H₂O, if the molar mass of FeS₂ is M, then equivalent mass of FeS₂ would be equal to:

The number of neutrons in a drop of water (20 drops =1mL) at 4°C

In the disproportion reaction: H₃PO₂ → PH₃ + H₃PO_3 The equivalent mass of H₃PO₂ is (m = molecular mass of H₃PO₂):

The concentration of C = 85.45% and H = 14.55% is not obeyed by which of the following formula:

In the reaction 3Cu + 8HNO₃ → 3Cu(NO₃)₂ + 2NO+ 4H₂O, what is the equivalent weight of HNO₃? (If the molecular weight of HNO₃ is M).

105 ml of pure water at 4°C is saturated with NH_3(g) producing a solution of density 0.9 gm/ml. If this solution contains 30% of NH₃ by mass, the total volume of solution is:

When 16.6 g of KI is treated with an excess of KIO₃ in the presence of 6NHCl, ICl is produced. The amount of KIO₃ consumed and the ICl formed are:

0.5 mole of H₂O is formed when one gram of H₂ react with how many grams of oxygen?

The compound which have same molecular and empirical formula:

Molecular formula of glucose is:

On complete combustion 44 gram of a sample of a compound gives 88 gram CO₂ and 36 gram of H₂O the molecular formula of the compound may be:

The empirical formula and molecular mass of a compound are CH₂O and 180 grams respectively the molecular formula of the compound is:

The empirical formula for water is:

An acid with molecular mass 104 contains 34.6% carbon 3.85% hydrogen and rest is oxygen the molecular formula of acid is:

Which of the following compound have empirical formula but no molecular formula:

During combustion analysis which one is used for absorbing carbon dioxide?

A compound contains 60% Mg and 40% O the empirical formula of compound is:

The empirical formula of chloroform is:

A compound X contains 50% sulphur and 50% oxygen by mass what is the empirical formula of X?

H-C contain 80% carbon in 20% hydrogen by mass the empirical formula is?

A substance X has found to contain 72% carbon 12% hydrogen and 16% oxygen what is the empirical formula of X?

Complete the molecular mass of sucrose (C₁₂H₂₂O₁₁) molecule?

The Empirical formula of glucose is:

During complete combustion with hydrocarbons, the sole products are:

A sample of AlF₃ contains 3.0 X 10²⁴ F^- ions. The number of formula units in this sample is:

Which among MnO₂, Mn₂O₃, MnO₃ and Mn₂O₇ contains the maximum percentage by weight of combined oxygen?

10 g of carbon burns giving 11.2 litres of CO₂ at STP. After combustion the amount of unburnt carbon is:

Lactose commonly used as a binder in tablets has a molecular weight of 342. What weight of CO₂ would be formed when 1/12 mole of this compound is burnt completely? (C₁₂H₂₂O₁₁ + 12O₂ 12CO₂ + 11H₂O)

A compound (60 g) on analysis gave C = 24 g, H = 4 g, O = 32 g. Its empirical formula is:

An oxide of metal (M) has 40% mass of oxygen. Metal M has a relative atomic mass of 24. The empirical formula of oxide is

How many seconds would it take to spend one Avogadro number of rupees at a rate of 6.02 x 10⁹ rupees per second?

How many water molecules will be lost on dehydrating 0.684 g of sucrose?

One mole of CO₂ contains:

The total number of protons in 10 g of calcium carbonate are: (NA=6.023x10²³)

What is the volume (in dm³) of oxygen at STP required for complete combustion of 32 g of CH₄? (mol. Wt of CH₄=16)

Maximum number of molecules will be in:

From the complete decomposition of 20g CaCO₃ at STP the volume of CO₂ obtained is:

The maximum number of molecules are present in:

One mole of CH₄ contains :

The mass of one molecule of a compound C₆₀H₁₂₂ is :

A compound possesses 8% sulphur by mass. The least possible molecular mass of the compound is:

A beaker contains 9 g of water. The number of hydrogen atoms are:

The volume occupied by 1.4g of N₂ at S.T.P is:

50 gram of calcium carbonate was completely burnt in air. What is the weight (in grams) of the residue:

The number of gram molecules of oxygen in 6.02x10²⁴ CO molecules is:

Which of the followings does not represent the empirical and molecular formula of the same compound?

Which series of organic compounds shares the same empirical formula:

The ratio of the volumes between equal masses of O₂, H₂ and CH₄ is:

The volume occupied by one gram of oxygen gas:

No. of hydrogen atoms in 45g of glucose:

The complete ionization of 36.5 g of HCI produces H⁺ ions

4.6g of C₂H₅OH & 3g of C₂H₆ have:

The mass of O₂ required to burn 0.1 mole of C₂H₅OH is:

The mass of SiC formed when 60g of SiO₂ is reacted with excess of Carbon:

The ratio of volume between 4 g of H₂ and 32g of CH₄ at STP is

What are the number of covalent bonds in 68 g of H₂S gas?

How many atoms are there in 0.125 moles of S₈ molecules?

Calculate number of moles of K₂SO₄ produced when 14g KOH are reacted with excess of H₂SO₄:

The maximum No. of moles are present in

The number of molecules of water that one needs to put in a jar to make the total mass equal to 10.8 kg are:

Which pair shows Empirical formula CH₂O?

4 g H₂ gas reacts with 8 g O₂ gas to form steam. How many moles of gases are there after the completion of reaction in vessel?

The number of protons in 1 mole of H₂:

From the complete decomposition of 0.2 moles CaCO₃ at S.T.P. the volume of CO₂ obtained is:

The number of moles of H₂O which contain 16g of oxygen:

24g each of carbon and oxygen react to form CO₂. The amount of unreacted element left behind is:

The number of carbon atoms in 6mg of a graphite piece is:

How many moles of CO₂ are produced from 0.9 moles of O₂ in the reaction C + O₂ CO₂:

The volume occupied by 16g of oxygen at STP is:

Given the equation CO_2(g) + C_(s) 2 CO_(g) Which of the following equivalences is not correct for the reaction:

Largest number of molecules is present in:

Calculate the number of grams of H₂O formed when 8g of CH₄ burns in excess of oxygen.

Determine the number of moles of oxygen in 10.6g of Na₂CO₃ :

The molar volume of SO₂ gas at STP is:

The weight of iron (Fe) which will be converted into Fe₃O₄ by the action of 18g of steam is: 3Fe + 4H₂O Fe₃O₄ + 4H₂

What volume of oxygen is required for the complete combustion of a mixture of 5cm³ of CH₄ and 5cm³ of C₂H₄?

How many atoms of carbon are present in 18g of glucose?

For complete combustion, 1 mole of an organic compound requires 8 moles of O₂ gas. What could be the formula of the compound?

The number of molecules in 5.6 dm³ of oxygen under STP conditions is:

Mass of 0.25 moles of SO₂ is:

H₂ burns in chlorine to produce hydrogen chloride. The exact mass of Cl₂ required to convert 4g H₂ into HCI according to the following equation H₂+Cl₂ 2HCl is:

27g of Aluminum reacts with how much O₂ to produce Aluminum oxide?

The number of molecules in 22g of CO₂ is:

Calculate the number of moles of Mg required to produce 11.212 dm³ of Hydrogen gas at STP when it reacts with HCl solution. The equation for this reaction is: Mg + 2HCl MgCl₂ + H₂

Signature of the person with lead pencil increased the weight of the paper by 1.2grams. How many atoms of carbon are present?

The mass of H-atom is 1.008 a.m.u. Its mass in kg is:

The number of moles of NO₂ which contains 16g of oxygen:

A polymer of empirical formula CH₂ has a molar mass of 28000gmol^-I. What is its molecular formula?

The largest number of molecules are present in:

Mg metal reacts with HCl to give hydrogen gas. What is minimum weight of HCI required to produce 12g of H₂?

Which of the following samples contain the largest number of atoms?

How many chlorine atoms are in 2 moles of Cl?

When one mole of each of CO, ethane, C (Diamond) and methane is completely burnt in oxygen, which will give the largest mass of CO₂?

What volume of oxygen is required for complete combustion of 5 cm³ of C₂H₂?

6Na + Fe₂O₃ 3Na₂O+ 2Fe For above reaction, if you are provided with 230 g Na and 320 g Fe₂O₃, then limiting reactant is:

An acid with molecular mass 104 contains 34.6% C, 3.85% H and rest is O. The molecular formula of acid is:

The sole products of combustion analysis are:

Absorption of CO₂ in KOH solution during combustion analysis is:

The relative atomic mass of oxygen is 16 amu. What is the mass of 2 mole of oxygen gas?

3x10^-21 moles of an amino acid having molecular mass 200 g mol^-1, would have molecules:

Number of electrons in half mole of Na⁺ :

Amount of oxygen in grams which contains 1.5×10²² molecules:

When 0.5 moles of Al₂(SO₄)₃ are dissolved in water, total number of particles produced are:

Number of H⁺ ions when 0.1 mole of sulphuric acid is completely ionized in water:

Which one is not true about isotope?

Absorption of CO₂ in KOH solution during combustion analysis is?

Which of the following is not true for a mole?

Amount of oxygen in grams which contains 1.5 × 10²² molecules:

The number of moles of CO₂ which contains 16g of oxygen:

How many electrons have to be removed to ionize 1.0 x 10^-6 moles of Ne atoms to Ne+ ions in a neon advertising tube?

Number of H⁺ ions when 0.1 moles of sulfuric acid is completely ionized in water:

When pentane C₅H₁₂ is burned in excess oxygen, the products of the reaction are CO_2(g) and H₂O_(l). In the balanced equation for this combustion,C₅H_12(g) _____ O_{2 (g)} → 5CO_2(g) + 6H₂O_(l) the coefficient of the oxygen should be:

The number of moles of Cr₂O₇ needed to oxidize 0.136 equivalent of N2H5 according to the reaction is: N₂H₅⁺ + Cr₂O₇ ^2- N₂ + Cr³⁺ + H₂O is:

12g carbon combines with 64g sulfur to produce CS₂. 12g carbon also combines with 32g oxygen to form CO₂. 10g sulfur combines with 10 g oxygen to produce SO₂ . These data illustrate the:

The pair of species having the same percentage of carbon is:

NH₃ is produced according to the following reaction: N_{2 (g)} + 3H_{2 (g)}→ 2NH_{3 (g)} In an experiment, 0.25 mol of NH₃ is formed when 0.5 mol of N₂ is reacted with 0.5 mol of H₂. What is the % yield?

A carbon compound containing carbon and oxygen has an approximate molar mass equal to 290. On analysis, it is found to contain 50% by mass of each element. Therefore molecular formula of the compound is: