Describe how to use the “difference method” when performing mass determinations. Why are masses in the chemistry laboratory usually determined by the difference method (using a beaker to contain the object to be weighted, rather than just placing the object directly on the pan of the balance)?

Pre-Laboratory Questions

Describe how to use the “difference method” when performing mass determinations. Why are masses in the chemistry laboratory usually determined by the difference method (using a beaker to contain the object to be weighted, rather than just placing the object directly on the pan of the balance)?

Why should the mass of an object never be determined while the object’s temperature is above room temperature?

If you weigh a hot object on the balance, the reading will be higher, the same, or lower than if it had been weighed after it cools to room temperature?

Why should liquids never be poured on or near the balance?

Why are masses in the chemistry laboratory usually determined by the difference method (using a beaker to contain the object to be weighted, rather than just placing the object directly on the pan of the balance)?

ACTIVITY OF WET LABS MEASURING THE MASS & VOLUME OF OBJECTS AND SUBSTANCES

Choose a Solid Object whose mass you will measure and describe the Solid Object in the appropriate location on the Data sheet.

Choose a container to use for determining the mass of the Solid Object; this will be Container A. Describe the type of container used in the appropriate location on the Data sheet.

Determine the Mass of the Solid Object by subtracting the Mass of Container A from the Mass of Container A and the Solid Object. Record the value on the Data sheet.

Describe how to use the “difference method” when performing mass determinations.

Why are masses in the chemistry laboratory usually determined by the difference method (using a beaker to contain the object to be weighted, rather than just placing the object directly on the pan of the balance)?

Why should the mass of an object never be determined while the object’s temperature is above room temperature?

If you weigh a hot object on the balance, the reading will be higher, the same, or lower than if it had been weighed after it cools to room temperature?

Why should liquids never be poured on or near the balance?