How many moles are in 25 grams of HF

A sample of pure iron has a mass of 5.00 g calculate its volume.

Calculate the wavelength of the light emitted when an electron in a hydrogen atom makes each of the following transitions. a. n = 2 - -> n = 1? b. n = 3 - -> n = 1? c. n = 4 - -> n = 2? d. n = 5 - -> n = 2?

1.86 g H2 is allowed to react with 9.75 g N2, producing 2.87g NH3. A. What is the theoretical yield in grams for this reaction under the given conditions? B. What is the percent yield for this reaction under the given conditions?

Sodium and water react according to the following equation. If 31.5g of sodium are added to excess water, how many liters of hydrogen gas are formed at STP? Show all work for credit. 2Na + 2H2O 2NaOH + H2

If you drop a 200 gram piece of metal with a temperature of 110 degrees Celsius into 1000 grams of water at 25° Celsius, what best describes what would occur?

In the chemical formula 3NO2 the number 3 is a

W (g) + X (g) - -> Y (g) + Z (g) Gases W and X react in a closed, rigid vessel to form gases Yand Z according to the equation above. The initial pressure of W (g) is 1.20 atm and that of X (g) is 1.60 atm. No Y (g) or Z (g) isinitially present.

In this process, a piece of paper with small holes in it separates a heterogeneous mixture by letting through the small particles and keeping out the big ones. That is called as

The double bond between carbon and oxygen is similar to an alkene C-C, except that C o is: a) shorter and weaker. b) shorter and stronger c) longer and weaker. d) longer and stronger.

Calculate the half-life (in s) of a first-order reaction if the concentration of the reactant is 0.0576 M 17.1 s after the reaction starts and is 0.0249 M 97.8 s after the reaction starts.