QQuestion
Calculate:
(a) The percentage of phosphorus in the fertilizer super phosphate Ca(H2PO4)2 correct to 1 decimal point.
(b) Write the empirical formula of C8H18
[At. Wt. H=1, P=31, O=16, Ca=40]
ICSEClass 10ChemistryMole Concept and Stoichiometry03 Mark2023 Moderate
✓Answer
(a) Formula mass of Ca(H₂PO₄)₂ = 40 + 2[2(1) + 31 + 4(16)] = 234.
Mass of phosphorus = 2 × 31 = 62.
\frac{62}{234}\times100=26.5\%(b) C₈H₁₈ = (C₄H₉)₂.
Empirical formula = C₄H₉.
Was this answer helpful?
Related Questions
More ICSE Moderate level questions
1/12
Ethane burns in oxygen according to the chemical equation: 2C2H6 + 7O2 → 4CO2 + 6H2O If 80 ml of ethane is burnt in 300 ml of oxygen, find the composition of the resultant gaseous mixture when measured at room temperature.
Match the Column A with Column B: Column A Column B (a) Sodium chloride 1. has two shared pair of electrons (b) Methane 2. has high melting and boiling points (c) Hydrogen chloride gas 3. a greenhouse gas (d) Oxidation reaction 4. has low melting and boiling points (e) Water 5. Zn − 2e− ⟶ Zn2+ 6. S + 2e− ⟶ S2−
Define / State: (a) Electronegativity. (b) Gay-Lussac’s law of combining volumes.
State the terms/process for the following: (a) The energy released when an atom in the gaseous state accepts an electron to form an anion. (b) Tendency of an element to form chains of identical atoms. (c) The name of the process by which Ammonia is manufactured on a large scale. (d) A type of salt formed by partial replacement of hydroxyl radicals with an acid radical. (e) The ratio of the mass of a certain volume of gas to the same volume of hydrogen measured under the same conditions of temperature and pressure.
Name the following: (a) Organic compounds with same molecular formula but different structural formula. (b) Group of organic compounds where the successive members follow a regular structural pattern, successive compounds differ by a 'CH2' group.
Fill in the blanks with the choices given in the brackets: (a) Metals are good ............... [oxidizing agents /reducing agents] (b) Non-polar covalent compounds are ............... [good / bad] conductors of heat and electricity. (c) Higher the pH value of a solution, the more is ............... [acidic / alkaline] it is. (d) ............... [Silver chloride / Lead chloride] is a white precipitate that is soluble in excess of Ammonium hydroxide solution. (e) Conversion of ethene to ethane is an example of ............... . [hydration / hydrogenation]
Arrange the following according to the instructions given in brackets: (a) C2H2, C3H6, CH4, C2H4 (In the increasing order of the molecular weight) (b) Cu2+, Na+, Zn2+, Ag+ (The order of Preferential discharge at the cathode)
Give the structural formulas and IUPAC names as directed: (a) Give the structural formula of the following organic compounds: 2-chlorobutane Methanal But-2-yne (b) Give the IUPAC name of the following organic compounds:
Study the reaction scheme shown below and identify the reactants A, B and C.
Zn + 4HNO3 ⟶ Zn(NO3)2 + 2H2O + 2NO2 32.5 g of zinc reacts with concentrated nitric acid as given in the above equation. (a) How many moles of zinc was required in the reaction? (b) Find the mass of nitric acid needed to react with 32.5 g of zinc. (c) Find the volume of nitrogen dioxide liberated in (b). [Atomic weight: H=1, N=14, O=16, Zn=65]
Given below are organic compounds labelled A to F. Answer the questions that follow: (a) Which compound forms a single product with bromine? (b) Which two compounds have the same molecular formula? (c) Which two compounds will react together in the presence of concentrated H2SO4 to form a product with a fruity smell?
Complete and balance the following equations: (a) Al2O3 + 2NaOH ⟶ (b) C2H5COONa + NaOH ⟶ (c) C2H4Br2 + alcoholic KOH ⟶