CHEMICAL CALCULATIONS- FINAL EXAM 1. Choose the response that includes all the i

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CHEMICAL CALCULATIONS- FINAL EXAM 1. Choose the response that includes all the items 8. Howmnyprotons listed below that are pure substances i. orange juice 111. Ocean water v. vegetable soup neutrons are in 4STi22 (A) 48 protons, 20 electrons, 22 neutrons (B) 22 protons, 24 electrons, 26 neutrons (C) 22 protons, 22 electrons, 26 neutrons (D) 22 protons, 20 electrons, 26 neutrons ii. steam V oxygen (B) ii, iv (C) iv only (D) all of them are pure How many sodium ions are in 25.0 g of Na2CO (Molar Mass: 105.99gmol? 9. (A) 1.13x 1020 ions (B) 7.10% 102) ions (C) 1.42 x 103 ions (D) 2.84 x 10 ions 2. Which one of the following represents a chemical change? (A) boiling water to form steam (B) burning a piece of coal (C) breaking glass 10 mg 4.02 x 10 lb ( kg 2.20 lb) (A) 8.8 x 10 mg (B) 1.8 x 10 mg (C) 1.8 x 10mg (D) 8.8 x 10 mg (D) mixing iron filings and sand at room temperature 11. What mass in grams of LiF is needed to make 500. mL of a 0.500M solution? 3. 2.4 km is how many millimeters? (A) 2.4 x 103 mm (B) 2.4 x 10 mm (A) 0.250g (C) 13.0 g (B) 6.49 g (D) 25.9 g 1 Do the arithmetic below and give the answer

Explanation / Answer

1. Steam and oxygen contains only water vapour and Oxygen respectively.

SO option (B) is correct.

2.A chemical change is a change of materials into other, new materials with different properties, and one or more new substances are formed and also you cannot get back the previous product. So option B is correct because others are just physical change.

3. 1 Km= 1000000 millimeter.

So 2.4 Km =2.4 x 10 ^6 millimeter

4. 48 represents the mass number

Titanium has atomic number of 22

So no of protons =22

no of neutrons = mass no- no of protons=48-22=26

No of electrons=22-2=20......... it has a charge of +2 so it has lost 2 electrons so thus we have subtracted 2 from no of protons.

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