CHE1501 ASSIGNMENT 1 2021

CHE1501

ASSIGNMENT 1 2021

QUESTION 1
 A homogeneous mixture is a type of mixture where two or more substances in same phase
or states for example a mixture of a solid to solid mixture.

An aqueous solution of sodium chloride and ink is a homogeneous mixture because sodium
chloride is in liquid phase so is the ink.

ANSWER: [3]

QUESTION 2
 A compound is a substance made up of two or more different elements chemically bonded
together

GLUCOSE: It is a compound made up of carbon, hydrogen and water.

ANSWER:[4]

QUESTION 3
ANSWER:[4]

QUESTION 4
ANSWER:[5]

QUESTION 5
ANSWER:[5]

QUESTION 6
 The charge on an ion indicates how many electrons where gained or lost in making up the
ion from a neutral atom. Positively charged ions are a results of loss of electrons and
negatively charged ions are a results of gain of electrons.

128 2−
52𝑇𝑒 :𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑒𝑙𝑒𝑐𝑡𝑟𝑜𝑛𝑠 𝑖𝑛 𝑎 𝑛𝑒𝑢𝑡𝑟𝑎𝑙 𝑎𝑡𝑜𝑚 = 52

𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑒𝑙𝑒𝑐𝑡𝑟𝑜𝑛𝑠 𝑔𝑎𝑖𝑛𝑒𝑑 = 2

𝑇𝑜𝑡𝑎𝑙 𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑒𝑙𝑒𝑐𝑡𝑟𝑜𝑛𝑠 𝑖𝑛 𝑡ℎ𝑒 𝑖𝑜𝑛 = 54

ANSWER:[2]

, QUESTION 7
 𝑚𝑎𝑠𝑠 𝑛𝑢𝑚𝑏𝑒𝑟 = 𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑝𝑟𝑜𝑡𝑜𝑛𝑠 + 𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑛𝑒𝑢𝑡𝑟𝑜𝑛𝑠

𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑛𝑢𝑒𝑡𝑟𝑜𝑛𝑠 𝑜𝑓 14.𝐶 = 14 − 6 = 8 𝑛𝑢𝑒𝑡𝑟𝑜𝑛𝑠

𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑛𝑢𝑒𝑡𝑟𝑜𝑛𝑠 𝑜𝑓 14.𝑁 = 14 − 7 = 7 𝑛𝑢𝑒𝑡𝑟𝑜𝑛𝑠

𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑛𝑢𝑒𝑡𝑟𝑜𝑛𝑠 𝑜𝑓 16.𝑂 = 16 − 8 = 8 𝑛𝑢𝑒𝑡𝑟𝑜𝑛𝑠

𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑛𝑢𝑒𝑡𝑟𝑜𝑛𝑠 𝑜𝑓 19.𝐹 = 19 − 9 = 10 𝑛𝑢𝑒𝑡𝑟𝑜𝑛𝑠

𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑛𝑢𝑒𝑡𝑟𝑜𝑛𝑠 𝑜𝑓 14.𝑁𝑒 = 20 − 10 = 10 𝑛𝑢𝑒𝑡𝑟𝑜𝑛𝑠

ANSWER:[2]

QUESTION 8
 Isotopes are species that have the same atomic number but different mass numbers.

ANSWER:[1]

QUESTION 9
∑(𝑎𝑡𝑜𝑚𝑖𝑐 𝑚𝑎𝑠𝑠) × (𝑝𝑒𝑟𝑐𝑒𝑛𝑡𝑎𝑔𝑒 𝑎𝑏𝑢𝑛𝑑𝑎𝑛𝑐𝑒)
𝐴𝑣𝑒𝑟𝑎𝑔𝑒 𝑎𝑡𝑜𝑚𝑖𝑐 𝑤𝑒𝑖𝑔ℎ𝑡 =
100
(35.9675 × 0.337) + (37.9627 × 0.063) + (39.9624 × 99.600)
𝐴𝑣𝑒𝑟𝑎𝑔𝑒 𝑎𝑡𝑜𝑚𝑖𝑐 𝑤𝑒𝑖𝑔ℎ𝑡 =
100

𝐴𝑣𝑒𝑟𝑎𝑔𝑒 𝑎𝑡𝑜𝑚𝑖𝑐 𝑤𝑒𝑖𝑔ℎ𝑡 = 39.9477 𝑎𝑚𝑢

From the periodic table the element with an atomic weight of 39.9477 is 𝐴𝑟𝑔𝑜𝑛

ANSWER:[1]

QUESTION 10
ANSWER:[4]

QUESTION 11
ANSWER:[3]

QUESTION 12
ANSWER:[3]