Apart from the power to propose and pass laws, Congress has several non-legislative powers including the following: powers to impeach, tax, amend the Constitution, declare war, elect the President in case there is no majority in the electoral college, ratification of treaties and trade agreements, confirmation of appointments and certain investigative powers. Some of these belong to the Senate and some to the House of Representatives.
The House of Representatives has the power to impeach the President, Vice President and certain other high officials, and the Senate tries the cases. Congress has the power to amend the Constitution with a two-thirds majority vote. The Senate has the power to approve appointments that require approval. If the appointment is for the office of Vice President, the House also must vote. The Senate has the power to approve treaties. If the treaty involves foreign aid, however, the House must also agree. If no candidate for President gets a majority in the electoral college, the House of Representatives decides between the three top candidates. The Senate must elect the Vice President. The Congress alone has the power to declare war. Both houses of Congress investigate certain issues that are of national interest and importance.