Answer:
carbon dioxideis the product
potassium + water is the product
Answer : The moles of methane gas could be, 
Solution :
According to the Graham's law, the rate of effusion of gas is inversely proportional to the square root of the molar mass of gas.
or,
![[\frac{(\frac{n_1}{t_1})}{(\frac{n_2}{t_2})}]=\sqrt{\frac{M_2}{M_1}}](https://tex.z-dn.net/?f=%5B%5Cfrac%7B%28%5Cfrac%7Bn_1%7D%7Bt_1%7D%29%7D%7B%28%5Cfrac%7Bn_2%7D%7Bt_2%7D%29%7D%5D%3D%5Csqrt%7B%5Cfrac%7BM_2%7D%7BM_1%7D%7D)
where,
= rate of effusion of fluorine gas
= rate of effusion of methane gas
= moles of fluorine gas = 
= moles of methane gas = ?
= time = 12.3 min (as per question)
= molar mass of fluorine gas = 38 g/mole
= molar mass of methane gas = 16 g/mole
Now put all the given values in the above formula 1, we get:
![[\frac{(\frac{5.13\times 10^{-3}mol}{12.3min})}{(\frac{n_2}{12.3min})}]=\sqrt{\frac{16g/mole}{38g/mole}}](https://tex.z-dn.net/?f=%5B%5Cfrac%7B%28%5Cfrac%7B5.13%5Ctimes%2010%5E%7B-3%7Dmol%7D%7B12.3min%7D%29%7D%7B%28%5Cfrac%7Bn_2%7D%7B12.3min%7D%29%7D%5D%3D%5Csqrt%7B%5Cfrac%7B16g%2Fmole%7D%7B38g%2Fmole%7D%7D)
Therefore, the moles of methane gas could be,
<span> Well, here are the characteristics of ionic compounds: 1) Because of the electrostatic force of attraction (one of the strongest force), these types of compounds are usually rigid. 2) High melting points (like REALLY high compared to other colavent compounds). Ex. table salt (NaCl melts at 1714 degrees fahrenheit, while CH4 melts at -295 degrees fahrenheit). See the drastic difference? 3) Majority of ionic compounds dissolve easily in water. Notice how I say majority, as some ionic compounds are insoluble in water, and this just have to do with their intermolecular attraction between themselves relative to that between the ions and water. If for any reason you need to know these solubility characteristics, just google solubility table or something along that line. 4) When dissolved in a solution, any ionic compound can conduct electricity because the ions are floating freely and can therefore transfer electrons around. In their solid form, however, they cant because all the ions are stuck in place and cant move around. 5) Ionic compounds form a really specific shape, and all the ions are orderly placed and evenly distributed in the crystal lattice. The geometric shape of the compound is a chemical property, which means that it varies across species.</span>
An educated guess is called estimation
