Lab 1 - Intro Lab Assignment - Matthew Whitney

Experiment 3 In this experiment, you heated a sample of a copper mineral to decompose it to simpler substances. 6. Record the mass values you measured and calculated in the table below. When recording mass values you measured, be sure to record all digits displayed by the balance output reading . a Mass of an empty crucible (g) 88.000g b Mass of the crucible with malachite, CuCO 3 Cu(OH) 2 (grams, g) 108.000g c Subtract (a) from (b) to obtain the mass of malachite CuCO 3 Cu(OH) 2 (grams, g) 20.000g d Mass of crucible after reaction is complete (with black solid), (g) 102.390g e Mass of black solid in crucible after reaction is complete (g) 14.390g f Change in mass of solid in crucible from Before Reaction to After Reaction (g) 5.610g 7. Write the balanced equation for decomposition of malachite. Include physical state symbols. (See Background in lab manual.) C u 2 CO 3 ( OH ) 2 ( s ) 2 CuO ( s ) + H 2 O ( g ) + CO 2 ( g ) 8. What does your calculated value in Row f in your data table represent? How would you account for the loss of mass? This value represents the mass of the black solid left in the crucible, minus the gaseous compounds that escaped. 9. Based on your data collected, (a) Record your calculated value for the total combined mass of the CO 2 gas and water vapor produced in the reaction. (b) Explain how you determined this value, and what "Law" is the basis for obtaining this value. (a) 5.610g (b) This value was obtained from taking the initial mass of 108.000g and subtracting the final mass of 102.390g. The basis for this is the Law of Conservation of Mass.