The answer is d: Combustion, because it is the so-called combustion of methan. (Check your lesson)
What? That docent make any scene?
The balanced equation for the above reaction is as follows
CaCO₃ + 2HBr ---> CaBr₂ + CO₂ + H₂O
stoichiometry of CaCO₃ to HBr is 1:2
number of moles of CaCO₃ reacted - 5.64 g / 100 g/mol = 0.0564 mol
according to molar ratio
number of HBr moles - 0.0564 mol x 2 = 0.1128 mol
number of HBr moles in 250.0 mL - 0.1128 mol
therefore number of HBr moles in 1000 mL - 0.1128 mol / 250.0 mL x 1000 mL = 0.4512 mol
molarity of HBr - 0.4512 M
The circumstances when scientists use observational research and opinion based research is when they include animals or things that cannot control for a product. Observational research is a type of research which only observes ongoing behavior and studies about it and the results only rely on the behavior observed.
Answer:
317.6 mL
Explanation:
Step 1: Write the balanced neutralization equation
MgO + 2 HCl ⇒ MgCl₂ + H₂O
Step 2: Calculate the mass corresponding to 640.0 mg of MgO
The molar mass of MgO is 40.30 g/mol. The moles corresponding to 640.0 mg (0.6400 g) of MgO are:
0.6400 g × (1 mol/40.30 g) = 0.01588 mol
Step 3: Calculate the moles of HCl that react with 0.01588 moles of MgO
The molar ratio of MgO to HCl is 1:2. The moles of HCl are 2/1 × 0.01588 mol = 0.03176 mol
Step 4: Calculate the volume of 0.1000 M HCl that contains 0.03176 moles
0.03176 mol × (1 L/0.1000 mol) = 0.3176 L = 317.6 mL