When 1 g of a cube of manganese (iv) oxide was added to 100 cm3 of hydrogen peroxide, water and oxygen were produced. manganese oxide was not used up in the reaction. based on this information, which of the following is likely to increase the rate formation of the products? using 2 grams of manganese oxide using 50 cm3 of hydrogen peroxide replacing the cube of manganese (iv) oxide with its powder removing manganese (iv) oxide from the reaction mixture

answer: c. the experiment shows that the red substance experienced a chemical change.

explanation: chemical change is the change in which chemical composition of the substance changes. physical change is the change in which there is no change in chemical composition.

chemical changes are accompanied by following changes:

a) precipitate formation

b) energy is released or absorbed

c) formation of bubbles

d) change in color

as it is given that the red color has disappeared and there is production of gas, it means the red substance has undergone a chemical change.

e

the mantle

explanation:

earth is divided into three layers: the crust or the outermost layer on which we live; the underlying, middle layer - the mantle - and the core (the innermost layer of earth).