ECAT Chemistry Online Test With Answers

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ECAT Chemistry Online Test

Sr. # Questions Answers Choice
1 A compound X contains 50% sulphur and 50% oxygen by mass. What is the empirical formula of compound X? SO SO<sub>2</sub> SO<sub>3</sub> SO<sub>4</sub>
2 One mole of ethanol and one mole of ethane have an equal Mass Number of atoms Number of electrons Number of molecules
3 Which has greater number of moles 0.1 g sodium 6.02 x 10<sup>20</sup>atoms of magnesium 20 cm<sup>3</sup>0.1<sup></sup>mole per dm<sup>3</sup>of NaOH 12.2 dm<sup>3</sup>of nitrogen at standard<div>[A<sub>r</sub>Na = 23, Mg = 24, O = 16]</div>
4 A compound having empirical formula C3H3O and its molecular mass is 110.02. Its molecular formula is C<sub>3</sub>H<sub>3</sub>O C<sub>6</sub>H<sub>6</sub>O<sub>2</sub> C<sub>9</sub>H<sub>9</sub>O<sub>3</sub> C<sub>3</sub>H<sub>6</sub>O<sub>2</sub>
5 A compound contains one atom of oxygen and % of O 34.78, then molecular mass of compound is 46 78 110 180
6 The percentage of which element in the organic compound is determined by the difference method Carbon Hydrogen Nitrogen Oxygen
7 The value of R(General Gas Constant) is <p class="MsoNormal"><span style="font-size: 10.5pt; line-height: 107%; font-family: Arial, sans-serif; background-image: initial; background-position: initial; background-size: initial; background-repeat: initial; background-attachment: initial; background-origin: initial; background-clip: initial;">8.3134 JK</span><sup><span style="font-size: 10.5pt; line-height: 107%; font-family: Arial, sans-serif;">-1</span></sup><span style="font-size: 10.5pt; line-height: 107%; font-family: Arial, sans-serif; background-image: initial; background-position: initial; background-size: initial; background-repeat: initial; background-attachment: initial; background-origin: initial; background-clip: initial;">mole</span><sup><span style="font-size: 10.5pt; line-height: 107%; font-family: Arial, sans-serif;">-1</span></sup></p><p class="MsoNormal"><sup><span style="font-size: 10.5pt; line-height: 107%; font-family: Arial, sans-serif;"><o:p></o:p></span></sup></p> <p class="MsoNormal"><span style="font-size: 10.5pt; line-height: 107%; font-family: Arial, sans-serif; background-image: initial; background-position: initial; background-size: initial; background-repeat: initial; background-attachment: initial; background-origin: initial; background-clip: initial;">1.987 Cal K</span><sup><span style="font-size: 10.5pt; line-height: 107%; font-family: Arial, sans-serif;">-1</span></sup><span style="font-size: 10.5pt; line-height: 107%; font-family: Arial, sans-serif; background-image: initial; background-position: initial; background-size: initial; background-repeat: initial; background-attachment: initial; background-origin: initial; background-clip: initial;">Mole</span><sup><span style="font-size: 10.5pt; line-height: 107%; font-family: Arial, sans-serif;">-1<o:p></o:p></span></sup></p> Both a and b <p class="MsoNormal"><span style="font-size: 10.5pt; line-height: 107%; font-family: Arial, sans-serif; background-image: initial; background-position: initial; background-size: initial; background-repeat: initial; background-attachment: initial; background-origin: initial; background-clip: initial;">1.987 JK</span><sup><span style="font-size: 10.5pt; line-height: 107%; font-family: Arial, sans-serif;">-1</span></sup><span style="font-size: 10.5pt; line-height: 107%; font-family: Arial, sans-serif; background-image: initial; background-position: initial; background-size: initial; background-repeat: initial; background-attachment: initial; background-origin: initial; background-clip: initial;">mole</span><sup><span style="font-size: 10.5pt; line-height: 107%; font-family: Arial, sans-serif;">-1</span></sup><o:p></o:p></p>
8 The empirical formula of a liquid compound is known to be C2H4O. What other information is needed to work out its molecular formula? The percentage composition of the compound The relative molecular mass of the compound The density of the compound The volume occupied by one mole of the compound
9 Which one of the following compounds does not have the empirical formula CH2O? Ethanoic acid, CH<sub>3</sub>CO<sub>2</sub>H Ethanol, CH<sub>3</sub>CH<sub>2</sub>OH Glucose, C<sub>6</sub>H<sub>12</sub>O<sub>6</sub> Methanal, HCHO
10 Which of the following compounds contains the highest percentage by mass of nitrogen? Ammonia, NH<sub>3</sub> Ammonium carbamate, NH<sub>2</sub>CO<sub>2</sub>NH<sub>4</sub> Ammonium carbonate, (NH<sub>4</sub>)<sub>2</sub>CO<sub>3</sub> Hydrazine, N<sub>2</sub>H<sub>4</sub>
11 Which of the following statements is not true? Isotopes with even atomic masses are comparatively abundant Isotopes with even atomic masses are comparatively abundant Isotopes with even atomic masses and even atomic numbers are comparatively abundant Isotopes with even atomic masses and odd atomic number are comparatively abundant
12 Isotopes differ in the Number of neutrons Number of protons Number of electrons Number of atoms
13 The relative abundance of the ions with a definite m/e value is measured by High pressure of vapours Strength of electric current measured Quantity of fast moving electrons Electron gas
14 The pressure of vapours when sent to the ionization chamber in mass spectrometer is 10<sup>-5</sup>to 10<sup>-6</sup>torr 10<sup>-6</sup>to 10<sup>-7</sup>torr 10<sup>-7</sup>to 10<sup>-8</sup>torr 10<sup>-3</sup>to 10<sup>-4</sup>torr
15 The relative abundance of Pb isotopes is 1.5% Pb204, 23.6% Pb206, 22.6% Pb207, 52.3% Pb208The relative atomic mass of Pb is 207.94 208.24 206.94 207.24
16 The empirical formula of a compound is CH2O. What may be the compound C<sub>2</sub>H<sub>5</sub>OH C<sub>6</sub>H<sub>5</sub>OH HCOOH
17 Ascorbic acid contains 40.92% carbon, 4.58%, hydrogen and 54.4% oxygen. The empirical formula is C<sub>3</sub>H<sub>4</sub>O<sub>3</sub> C<sub>2</sub>H<sub>4</sub>O<sub>3</sub> C<sub>3</sub>H<sub>5</sub>O<sub>4</sub> C<sub>2</sub>H<sub>3</sub>O<sub>1</sub>
18 The percentage of H is the highest in CH<sub>4</sub> NH<sub>3</sub> H<sub>2</sub>SO<sub>4</sub> C<sub>6</sub>H<sub>12</sub>O<sub>6</sub>
19 Mass spectrometer measures the Exact mass of an element Average mass of an element The number of elements present in a molecule m/e value of a positive ion
20 The relative atomic mass of chlorine is 35.5. What is the mass of 2 mol of chlorine gas 142 g 71 g 35.5 g 18.75 g
21 Relative atomic mass of an element is the mass of the element relative to 1/12 mass of carbon-12 1/12 mass of carbon 1 mass of hydrogen atom 1/16 mass of oxygen
22 X-ray work has shown that the diameters of atom are of the order of 8 x 10<sup>-10</sup>m 2 x 10<sup>-10</sup>m 8 x 10<sup>-8</sup>m 2 x 10<sup>-8 </sup>m
23 A molecular ion is formed by Passing a high energy electron beam through gaseous molecule Dissolving a salt i dilute acid Passing electric current through molten salt Passing electricity through aqueous solutions
24 A beaker contains 9 grams of water. The number of H atoms is 6.02 x 10<sup>23</sup> 3.01 x 10<sup>23</sup> 6.02 x 10<sup>24</sup> 3.01 x 10<sup>24</sup>
25 Where energy is released during a reaction it is Exothermic reaction Endothermic reaction A free radical reaction A bond breaking reaction
26 Al3+is a symbol for aluminium Atom Ion Cation Anion
27 Which of the following statement is correct for a chemical reaction to occur molecules of substances must Collide with each other Collide with energy more than activation energy Collide with energy less than activation energy Collide with high frequency
28 Each molecule of haemoglobin is 68000 times heavier than one atom of C H N O
29 A molecule of haemoglobin is made up if nearly 10,000 atoms 50,000 atoms 2500 atoms 1500 atoms
30 Which one of the following statements is not correct A molecule is the smallest particle of an element which can exist independently He is a molecule of helium S<sub>8</sub>is a molecule of sulphur O<sub>3</sub>is a molecule of oxygen
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