A tax shifts the supply curve to the left. However, the impact of a tax depends on the elasticity of demand. If demand is inelastic, a higher tax will cause only a small fall in demand. Most of the tax will be passed onto consumers. When demand is inelastic, governments will see a signficant increase in their tax revenue.
Diagram of Tax on inelastic demand
If demand is elastic, demand will fall more. The tax will be more effective in reducing demand, but less effective in raising revenue for the government
Effect of Tax on Elastic Demand
Video of Elasticity
(sorry diagrams are not so visible)