1) how much volume would 2.00 moles of gas take up, under standard temperature and pressure conditions?

11.2 l

22.4 l

33.6 l

44.8 l

2) using the equation, c5h12 + 8o2 → 5co2 + 6h2o, if an excess of pentane (c5h12) were supplied, but only 4 moles of oxygen were available, how many moles of water would be produced?

1 mole

2 moles

3 moles

6 moles

3) the formation of sodium hydroxide occurs by adding sodium to water in this reaction:

2na + 2h2o → 2naoh + h2

a byproduct of the reaction is hydrogen gas. if 69 grams of sodium fully reacts with water, how many grams of h2 gas are produced?

1.0 gram

2.0 grams

3.0 grams

6.0 grams

answer: enthalpy

explanation:

for a exothermic reaction, the energy is released i.e. the energy of the products is lower than the energy of the reactants.

= enthaply

= energy of products

= energy of reactants

as , thus comes out to be negative. negative value of enthalpy shows that the reaction is exothermic.

6.4 cm (max) - 25 cm (min)

bcde is the incorrect answer it is a

answer: atomic mass was originally used to arrange elements on the periodic table, but is no longer used to organize the modern version.

explanation:

originally atomic mass was used to arrange elements on the periodic table from left to right in a row. each column then shows similar properties of elements of a group.

in modern periodic table, the atoms are arranged in increasing atomic number. as atomic number represents the number of protons in an atom which is unique for every atom.