Maharashtra State Board
- Show the dissociation of the following compounds on dissolving in water, with the help of chemical equation and (i) HCl underrightarrowwater H^(+ )+ Cl⁻ Dissociation is large (ii) NaCl underrightarrowwater Na⁺ + Cl⁻ Dissociation is large (iii) KOH unde... 2
- Formation of a magnesium chloride from magnesium and chlorine. Atomic number of Magnesium atom is 12. Electronic configuration is : Mg = 2, 8, 2 So it contains 2 valence electron. In order to achieve the... 1
- Formation of sodium chloride from sodium and chlorine. Atomic number of Sodium (Na) atom is 11. Electronic configuration is: Na = 2, 8, 1 So it contains 1 valence electron. In order to achieve th... 1
- Classify the following oxides into three types and name the types. CaO, MgO, CO2 , SO3 , Na2O, ZnO, Al2O3 , Fe2O3 1) Acidic Oxides: CO₂ (Carbon dioxide), SO₃ (Sulfur trioxide) 2) Basic Oxides: CaO (Calcium oxide), MgO (Magnesium oxide), Na₂O (Sodium oxid... 1
- Dilute H2SO4 was taken in an electrolytic cell and electric current was passed through it. When a dilute solution of sulfuric acid is electrolysed, gases are produced at both the anode and the cathode electrode. The gas produced at... 1
- Pieces of blue vitriol were heated in a test tube. On cooling, water was added to it. When pieces of blue vitriol are heated in a test tube, then crystal structure of blue vitriol broke down to form a colourless powder and wat... 1
- Dilute HCl was added to limestone. Limestone is calcium carbonate. When Dilute HCl was added to limestone, it forms calcium chloride, water and carbon dioxide gas. 2HCl + CaCO... 1
- Zinc oxide was added to dilute HCl and zinc oxide was added to dilute NaOH. When Zinc oxide is added to dilute HCl, it forms zinc chloride and water and neutralization reaction takes place. In this reaction zinc oxid... 1
- Magnesium oxide was added to dilute HCl and magnesium oxide was a added to dilute NaOH. Bases react only with oxides of non-metal to form salt and water and neutralization reaction take place. Magnesium oxide is a base. When Mag... 2
- A litmus paper was dropped into 2ml dilute HCl. Then 2ml concentrated NaOH was added to it and stirred. When litmus paper is dipped into 2 mL of dilute HCl solution , then blue litmus paper is turned into red colour and there is no effect on re... 1
- Two or three filings of copper were added to 10ml dilute nitric acid and stirred. Answer: Copper dissolves slowly, the solution turns blue (copper nitrate forms), and a colourless gas, nitric oxide (NO), is given off, whic... 1
- Two drops of the indicator phenolphthalein were added to 10ml solution of sodium hydroxide. When two drops of Phenolphthalein indicator are added to 10 mL solution of Sodium hydroxide, then the solution turns light pink in colour be... 1
- 50ml water is added to 50ml solution of copper sulphate. Write down the changes that will be seen in each Answer: The blue colour of the solution becomes lighter (paler); no chemical reaction takes place. Copper sulphate solution is blue because... 1
- Identify the odd one out and justify. (a) Chloride, nitrate, hydride, ammonium (a) Chloride, nitrate, hydride, ammonium Answer Ammonium - Ammonium is odd because Ammonium is cation and rest are anions. (b) Hydrogen chlo... 1
- Explain structure and bonding of diborane. Electronic configuration of boron is 1s² 2s² 2p¹. Thus, it has only three valence electrons. In diborane, each boron atom is sp³ hybridized.... 1
- Explain the trend in oxidation state of elements from nitrogen to bismuth. Group 15 elements have five valence electrons (ns² np³). Common oxidation states are -3, +3 and +5. The range of oxidation state is from -3... 1
- What are silicones? Where are they used? Silicones are organosilicon polymers having R₂SiO (where, R = CH₃ or C₆H₅ group) as a repeating unit held together by Since the empirical fo... 1
- Find out the difference between White phosphorus and Red phosphorus White phosphorus Red phosphorus It consists of discrete tetrahedral P₄ molecules. It consists chains of P₄ molecules linked together by cova... 1
- Find out the difference between Diamond and Graphite Diamond Graphite It has a three-dimensional network structure. It has a two-dimensional hexagonal layered structure. In diamond, each carbon... 1
- Name a molecule having banana bond. Diborane (B₂H₆) 2
- What is hybridization of Al in AlCl3? Al is sp² hybridized in AlCl₃. 2
- Explain the trend of the following in group 13 elements : A. atomic radii B. ionization enthalpy C. electron affinity A. Atomic radii: In group 13, on moving down the group, the atomic radii increases from B to Al. However, there is an anomaly observed in th... 1
- Give the formula of a compound in which carbon exhibit an oxidation state of A. +4 B. +2 C. -4 A. CCl₄ B. CO C. CH₄ 2
- PbCl4 is less stable than PbCl2 i. Pb has electronic configuration [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p². ii. Due to poor shielding of 6s² electrons by inner d and f electrons, it is diff... 1