Meaning of hypotheis

According to the law of conservation of matter, which chemical equation represents a possible chemical reaction? A. C + 2H2 CH4 B. 2H2 + O2 NH3 C. 2Al2O3 2Na2O D. N2 + 3H2 P4O10

If you started with 1000 units of a radioactive element that has a half-life of 2,500 years, how many half-lives will the material have gone through in 7500 years? (Show work and explain answer).

Use the data from this table of thermodynamic properties to calculate the values of ΔS°rxn for each of the following reactions at 25 °C.

The volume of gas is 250mL at 355kPa. What will the volume be when the pressure is reduced to 76.0kPa?

What might be useful for adding solids to a tube A / syringe B / wire crimpers C / funnel D / shovel

Benzene, C6H8, has an enthalpy of fusion = 10.19 kJ/mol. Calculate the amount of energy which is needed to change 88.0 g of solid benzene at 5.53°C into liquid benzene, also at 5.53°C?

What is the H3O + ion concentration of a solution that has an OH - ion concentration of 1.0 * 10^-3M? A) 1.0 * 10^-3M B) 1.0 * 10^-7M C) 1.0 * 10^-11M D) 1.0 * 10^-14M

Given the following chemical reaction: 2 O2 + CH4 CO2 + 2 H2O In the reaction of 6 moles of CH4 with excess oxygen, how many moles of water could be produced? 6 C 12.01 Carbon 1 H 1.01 Hydrogen 8 O 16.00 Oxygen A. 4 B. 6 C. 8 D. 12

Most mutagens have what kind of an effect on an organism?

According to the hess's law, the enthalpy of solution is: δhsoln = δhsolute + δhsolvent + δhmix. considering dissolving a small drop of nonpolar pentane oil in water which term (s) in the equation will experience the largest enthalpy change.