A sample of brass is melted and poured into a mold to make a musical instrument. Which of the following correctly explains why brass is classified as a homogeneous mixture?
The components of brass are uniformly distributed and cannot be distinguished visually
Brass is an alloy of copper and zinc. In a homogeneous mixture the constituents are blended so evenly that the composition is the same throughout and the separate components cannot be told apart by the eye; this is exactly the case in brass.
"Chemically bonded and cannot be separated" is wrong: in a mixture the metals are not joined by chemical bonds, and they can be separated by physical or chemical means; the components keep their own properties.
"Made of only one type of atom" is wrong because brass contains two different metals (copper and zinc), not a single kind of atom.
"A compound formed by the reaction of zinc and copper" is wrong because brass is a mixture in a fixed-looking but variable ratio, not a chemical compound with a fixed formula.
Hence, brass is a homogeneous mixture because its components are uniformly distributed and cannot be distinguished visually.
The molecular mass of carbon dioxide is:
What happens when acid is dissolved in water?
Which of the following statements are correct in relation to the extraction of metals? The metals which lie high in the reactivity series are extracted by the electrolysis of molten ore.
The metals of medium reactivity series exist as sulphides and carbonates in nature. It is easier to extract a metal from its sulphide in comparison to oxides.
Which of the following statements best explains why dry HCl gas does NOT change the colour of dry litmus paper, but aqueous HCl does?
Which of the following is NOT a property associated with compounds?
What is the purpose of enrichment of ore before extraction?
Which statement best describes an olfactory indicator?
In electrolytic refining, the impure metal is used as which of the following?
Which of the following 'indicators' is used to test the nature of solutions besides litmus paper?
Which of the following given below is an alloy of mercury?
The chemical symbol of potassium is _______.
In a molecule of water, the ratio of the mass of hydrogen to that of oxygen is:
Which is the element having the highest atomic mass among the following?
Each water molecule, contains _______ hydrogen atoms and one Oxygen atom.