The density of platinum is 23.4 g/cm3

. Calculate the mass of 75.0 cm3

of platinum.

In the reaction Mg (s) + 2H2O (l) Mg (OH) 2 (s) + H2 (g), what is the oxidation state of each H in H2 (g) ? A. 0 B. + 2 and - 2 C. + 1 D. - 1 and + 1

Naturally occurring bromine is composed of 50.7% of 79Br and 49.3% of 81Br. Atoms of 79Br have a mass of 78.9183 u and those of 81Br have a mass of 80.9163 u. Calculate the average atomic mass of bromine. Enter your answer with 3 significant digits.

What do scientists measure by using a triple-beam balance? Weight Mass Volume Density

Aluminum oxide, Al2O3, is used as a filler for paints and varnishes as well as in the manufacture of electrical insulators. Calculate the number of moles in 47.51 g of Al2O3.

In the equation PbO2 + 4HCl → 2H2O + PbCl2 + Cl2, how many electrons are transferred? A. 1 B. 2 C. 3 D. 4

Is ammonia acidic or alkaline?

How would you prepare 50.0 ml of 0.600 m hno3 from a stock solution of 4.00 m hno3? what volume (in ml) of the 4.00 m hno3 solution will you need?

Which volcanoes are located on a diverging boundaries

What is the chemical formula for the chemical reaction that occurs when a bath bomb is placed in water?

Which is most likely why many scientists reject the cold fusion theory? There is too much waste involved in the process. Cold fusion experiments have been conducted at room temperature only.