Answer:
A combustion reaction is a reaction that involves a substance and oxygen reacts at high temperature and produces light energy and thermal energy and generate light and heat.
If a flame is in a sealed container it will go out due to the absence of oxygen to perform a combustion reaction that requires oxygen to produce heat and light. A flame is the result of a combustion reaction which also requires the oxygen to keep on burning.
Arguably A, B and C are all correct. Atoms of elements can form compounds such as NaCl(table salt). Molecules form molecular compounds and minerals are just complex molecule compounds.
Answer:
A solid residue of limestone and some gypsum.
Explanation:
In step 2, some of the limestone and gypsum in the chalk dissolve in the water. When the mixture is filtered, the dissolved substances remain in the water. When the water is boiled off or evaporated, the solid substances remain behind.
Answer:
molarity = 0.385 moles/kg
Explanation:
Assume that the volume of the aqueous solution given is 1 liter = 1000 ml
Now, density can be calculated using the following rule:
density = mass / volume
Therefore:
mass = density * volume = 1.23 * 1000 = 1230 grams
Now, 0.467 m/L * 1L = 0.467 moles of HCl
We will get the mass of the 0.467 moles of HCl as follows:
mass = molar mass * number of moles = (1+35.5)*0.467 = 17.0455 grams
Now, we have the mass of the solution (water + HCl) calculated as 1230 grams and the mass of the HCl calculated as 17.0455 grams. We can use this information to get the mass of water as follows:
mass of water = 1230 - 17.0455 = 1212.9545 grams
Finally, we will get the molarity as follows:
molarity = number of moles of solute / kg of solution
molarity = (0.467) / (1212.9594*10^-3)
molarity = 0.385 mole/kg
Hope this helps :)
