What must models and theories do in order to remain valid? Provide 2 facts.

Given the following balanced reaction between nitrogen gas and oxygen gas to produce nitrous oxide gas, how many moles of nitrous oxide gas are produced from 1.65 moles of nitrogen gas?

1. What is the weight of the ethyl alcohol that exactly fills a 200.0 mL container? The density of ethyl alcohol is 0.789 g/mL

Hypothesize why bog acids react differently with the bones of the bodies than they do with the organs, hair and skin

Two samples of Mg (s) of equal mass were placed in equal amounts of HCl (aq) contained in two separate reaction vessels. Particle representations of mixing of Mg (s) and HCl (aq) in the two reaction vessels are shown in Figure 1 and 2 above.

Gold has a specific heat of 126 J / (kg! K). A sculptor increased the temperature of a 0.5 kg block of gold by 10°C. How much energy did the sculptor add to the gold?

If the molar mass of NaCl is 58.44 g/mol, what amount of NaCl (in mol) is contained in 250.0 mg of NaCl?

Which has more surface area, a rock the size of your hand or a handful of small rocks?

4Al (s) + 3O2 (g) - >2Al2O3 (s) the reaction is started by mixing 10.0g of Al and 10.0g of O2. What is the limiting reaction and how much Al2O3 is produced?

F 3.84 moles of methane are consumed in this reaction, how many moles of HCN will be produced?

Two metals with equal mass and different heat capacities are subject to the same amount of heat; which undergoes the smallest change? a) The metal with the higher heat capacity. b) The metal with the lower heat capacity.