Chemistry Flashcards
What is a synthesis reaction?
When two elements are added to become one compound.
What is a decomposition reaction?
When one compound is split into two or more elements.
2H2O - 2H2 + O2
What is an oxidation reation?
When oxygen is in the compound or equation (O2)
Are elements and compounds pure substances?
Yes, these are pure substances because they are made up of only one type of particle that possesses its own properties.
What is the difference between a heterogeneous mixture and a homogeneous mixture?
Homogeneous mixtures are made up of at least two pure substances whose particles are uniformly distributed. In this mixture, a solute is dissolved in another substance the solvent to form a solution (shows only one phase).
A heterogeneous mixture is made up of at least two pure substances whose particles are not uniformly distributed. This type of mixture is made up of at least two phase that are visible to the naked eye or under the microscope.
Is sand in water a heterogeneous or homogeneous mixture? Why?
It is a heterogeneous mixture because the sand is not evenly distributed throughout the water, it sinks to the bottom. And there are two visible phase, liquid (water) and solid (sand).
What is the difference between a physical/ mechanical change and a chemical change?
A mechanical change occurs when the appearance of a substance is changed without changing its nature.
A chemical change takes place when two or more substances, called reactants, interact to create new substances called products.
What is the equation for density?
g/ml (density)= m (mass) / v (volume)
What are the units for mass and volume?
Mass= g
Volume= ml
What colour will blue litmus paper turn if it is acid?
red
What colour will blue litmus paper turn if it is neutral?
blue
What colour will red litmus turn if it is base?
Blue
What colour will red litmus turn if it is neutral?
Red
If pH is 0-7 the liquid is a base or acid?
acid
If pH is 7-14 the liquid is a base or acid?
base
