An unknown compound has the following mass percent composition: 63.15% carbon, 5.30% hydrogen and 31.55% oxygen. What is the empirical formula of the compound.

A golden-colored cube is handed to you. The person is saying that it is a gold nugget. You pull out your old geology text and look up gold in the mineral table, and read that its density is 19.3 g/cm3. You also read that the density of pyrite (a.k.a. fool’s gold) is close to 4.75 g/cm3. You measure the cube and find that it is 1.05 cm on each side, and weighs 5.496 g. a) What is its density in g/cm3? b) What is its density in g/ml? c) Is it gold or pyrite? Show all your work. Use units and correct number of significant figures.

Combustion analysis of 25.0 g of octane (C8H18) determined that the sample contained 21.03 g of carbon. What is the percent by mass of hydrogen present in octane?

A compound is determined to contain 6.96 g carbon, 0.834 g hydrogen and 2.21 g oxygen. Determine the empirical formula of the compound

How much energy is required to raise the temperature of 40.9 g of zinc by 38.1oC? The specific heat capacity of zinc is 0.388 J/g°C.

What distinguishes a process delay from a lot delay in Shingo’s process elements?

How much energy is required to raise the temperature of 40.9 g of cobalt by 38.1oC? The specific heat capacity of cobalt is 0.46 J/g°C.

Complete the following reaction Ca(NO3)2(aq) + Na3PO4(aq)  →   a) by writing balanced total equation. b) by writing balanced ionic equation. c) by writing balanced net-ionic equation.

What is the significance of rework as a lean metric?

How many significant figures (or digits) are in each of the following number, when rounded to three decimal places? a) 10.03062 g b) 0.01785 cm c) 8.7884 mm How many significant figures (or digits) are in each of the following numbers? d) 9.008 g e) 120 cm f) 0.00010 mm g) 4 cats