An 0.648 g sample of isobutene contains 0.556g of carbonand the rest is hydrogen. 0.5 mol of isobutene has a mass of 28.5g. what is the empirical formula and molecular formula?

In order for a chemical reaction to occur there must always be

How does atomic radius change from left to right across a period in the periodic table? a. It first decreases, then increases. b. It tends to decrease. c. It first increases, then decreases. d. It tends to increase.

1. Calculate the [H] in a solution that has a pH of 9.88. A) 4.1 M B) 9.9 M C) 7.6 x 10'M D) 1.3 x 10 "M E) none of these

A radio station transmits its signal at 94.1 MHz. What is the wavelength of the signal? 1. 0.00319 m 2. 319 m 3. 3.19 m 4. 3.19 * 106 m

How many moles of barium hydroxide can be produced from the reaction of 4.234 moles of barium with 8.902 moles of water according to the following reaction? Ba + 2 H2O Ba (OH) 2 + H2

25 In general, for a gas at a constant pressure, A the temperature of the gas is inversely proportional to its volume B. the temperature of the gas is inversely proportional to its pressure C.

The vapor pressure of ethanol is 54.68 mm Hg at 25 °C. A nonvolatile, nonelectrolyte that dissolves in ethanol is saccharin. Calculate the vapor pressure of the solution at 25 °C when 8.054 grams of saccharin, C7H5NO3S (183.

What do microscopic producers supply the atmosphere with?

A particular form of electromagnetic radiation has a frequency of 8.11 x 10^14 hz. What is the energy in joules of one quantum of this radiation?

Which transition elements in the first transition series have anomalous electron configurations?