Answer: There are 0.056 moles present in 3.45 g of .
Explanation:
Given : Mass = 3.45 g
Moles is the mass of substance divided by its molar mass.
Hence, moles of (molar mass = 61.98 g/mol) is as follows.
Thus, we can conclude that there are 0.056 moles present in 3.45 g of .
Answer : The chemical formula of pure substances are different from those of mixtures because all the matter that exists on earth can be classified into two categories namely; pure substances and mixtures.
A pure substance always consists of a single element or compound. Example Oxygen is formed only of oxygen (O) atoms; whereas the table salt which is formed only by sodium chloride (NaCl) molecules is a compound which is made up of pure elements. A pure substance cannot be further divided into its components.
A mixture is made up of different compounds and/or elements. It can be easily separated using any physical method. Example, sand, salt and saw dust mixed together as a mixture. Also, it will not have a definite chemical formula.
Please refer the attachment for better understanding.
Answer:
Empirical formula is Au₂O₃
Explanation:
Given data:
Percentage of oxygen = 11%
Percentage of gold = 89%
Empirical formula = ?
Solution:
Solution:
Number of gram atoms of O = 11 / 16 = 0.69
Number of gram atoms of Au = 89 / 197 = 0.45
Atomic ratio:
Au : O
0.45/0.45 : 0.69 /0.45
1 : 1.5
Au : O = 1 : 1.5
Au : O = 2( 1 : 1.5)
Empirical formula is Au₂O₃.