Gaseous State

The gaseous mixture commonly used for welding metals is acetylene (C H ) and oxygen (O ). This mixture is used in oxy-acetylene welding, where acetylene burns in the presence of oxygen to produce a high-temperature flame (around 3,500°C), which is sufficient to melt and join metals. Among the options, C H (ethylene) and C H (butane) are not typically used for welding, and N (nitrogen) is not a suitable gas for creating the necessary flame. Thus, the correct answer is C H , O .

The total pressure exerted is 1 bar. The partial pressure of a component in a mixture is proportional to its mole fraction. Given the weight percentages of H and He, we can calculate the mole fractions, and hence, the partial pressures of each gas. This gives us 0.625 bar for H , 0.250 bar for He, and 0.125 bar for O .

Step 1: Assume total mass of mixture = 100 g.
Step 2: Calculate moles of each gas.
Step 3: Find mole fraction of O .
Step 4: Find partial pressure of O . Final Answer:

The graph shows a relationship between the log of and the log of pressure. By applying the equation for the graph at the given pressure, we can calculate . From the equation, we get: Using the known logarithmic values for , we compute the value of . Thus, the value of at the pressure of 0.3 atm is .

We can use the ideal gas law ( ) and the concept of partial pressures. Since the temperature is constant, we can use the relation for each gas. For H : , , . So, . For O : , , . So, . The total pressure of the mixture is the sum of the partial pressures: $ $

Step 1: Use kinetic energy formula.
Kinetic energy of gas is given by: Step 2: Convert given mass to kg.
Step 3: Substitute values.
Step 4: Since 8 g of H corresponds to 4 moles (molar mass = 2 g/mol), multiply by number of molecules.
Alternatively, continuing the classical approach: Correct energy is calculated for whole mass using .

Step 1: Use Dalton’s Law of Partial Pressures.
Given: So, Step 2: Assume ideal gas behavior and equal volume, use molar ratio based on pressure.
Step 3: Convert to masses.
Step 4: Calculate w/w % of H .