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## CHEMISTRY P.U.C. FIRST YEAR (MIDTERM) ### PART D **VI. Answer any TWO of the following. Each question carries Five marks.** 1. **a)** Explain principle and calculation involved in the estimation of carbon and hydrogen in an organic compound. **b)** Write the functional group for i) Nitrile...

## CHEMISTRY P.U.C. FIRST YEAR (MIDTERM) ### PART D **VI. Answer any TWO of the following. Each question carries Five marks.** 1. **a)** Explain principle and calculation involved in the estimation of carbon and hydrogen in an organic compound. **b)** Write the functional group for i) Nitrile ii) ketones. 2. **a)** For the compound H3C-CH2-CH=CH-CHO. Identify sp3 and sp2 hybridised carbon atom. **b)** What are aliphatic compounds? Give an example. **c)** Give an example of electrophile. 3. **a)** What is Homolytic cleavage? Give an example **b)** What are carbocation? Write the decreasing order of stability among 1o 2o and 3o carbocations. **c)** Write resonance structure of benzene. 4. **a)** Describe estimation of halogen by carius method. **b)** How do you detect nitrogen by Lassaigne test ? **VII. Answer any Four of the following. Each question carries three marks.** 1. **a)** A compound contains 26.67% carbon, 2.22% hydrogen and 71.11% of oxygen. Its molar mass is 90 g mol-1. Calculate its empirical and molecular formula (Atomic mass of C=12, H=1 and O=16) 2. Calculate molar mass C2H5OH and calculate percentage composition of C in C2H5OH. 3. Calculate molarity of sucrose (C12H22O11) if 10 g of sucrose is dissolved in enough of water to make final volume of 500mL. 4. Calculate the wave number and wavelength of photon emitted for Hα in Balmer series of hydrogen spectrum (Given RH = 1.09677 x 107 m-1). 5. If the velocity of the electron in Bohr's first orbit is 2.19 x 106 ms-1, calculate the de-Broglie wavelength associated with it. 6. Calculate energy of one mole of photons of radiation whose frequency is 5 x 1014 Hz. (Given: Planck's constant h = 6.626 x 10-34 Js) 7. Vividh Bharati station of All India Radio broadcast on frequency of 1368 Hz. Calculate wavelength and wave number of electromagnetic radiation. (Given: velocity of electromagnetic radiation is 3 x 108ms-1) 8. Threshold frequency [νo] for a metal is 7.0x1014 s-1.Calculate kinetic energy of an electron emitted. When radiation of frequency 1.0x1015 s-1 hits the metal. (Given: Planck's constant h=6.626 x 10-34 Js)