Answer:
We are heating the sample repeatedly to become a pure compound of only MgSO4 (withot H2O) and a constant mass.
Explanation:
Step 1: Data given
Mass of MgSO4·7H2O = 5.06 grams
The remaining MgSO4 had a constant mass of 2.47 grams.
Step 2: Explain why the sample in the crucible was heated repeatedly until the sample had a constant mass.
Before heating the compound has magnesium sulfate and water.
The total mass of this compound is 5.06 grams
By heating we try to eliminate the water.
After heating there remain mgSO4 with a mass of 2.47 grams
This means 5.06 - 2.47 = 2.59 grams is water. All of this is eliminated.
The heating process happens repeatedly to make sure the final compound is pure. So the 2.47 grams os only MgSO4. If the mass would not be constant. It means the compound is not pure, the not all the water is eliminated yet.
So we are heating the sample repeatedly to become a pure compound of only MgSO4 (withot H2O) and a constant mass.
Answer:
The correct answer is B.
Explanation:
Heterogeneous equilibrium is that in which reagents and products are present in more than one phase.
When the reaction is carried out in a closed container, three equilibrium phases are present: solid magnesium oxide, solid magnesium sulfate and gaseous sulfur trioxide.
Hence, the equilibrium contant is given by:
![K=\frac{[MgSO_4]}{[MgO][SO_3]} =\frac{1}{[SO_3]}](https://tex.z-dn.net/?f=K%3D%5Cfrac%7B%5BMgSO_4%5D%7D%7B%5BMgO%5D%5BSO_3%5D%7D%20%3D%5Cfrac%7B1%7D%7B%5BSO_3%5D%7D)
The concentrations in the equilibrium equation are the relationships of the real concentrations between the concentrations in the standard state. Since the standard state of a pure solid is the pure solid itself, the ratio of concentrations for a pure solid is equal to one.
Now, we analyse each statement:
I) As the reaction is endothermic (ΔH>0), increasing the temperature shifts the balance to the right because excess heat will be used to form more products.
II) Increasing the volume will decrease the concentration of SO₃, so Q>K and then this shifts the balance to the left.
III) As it is a heterogeneous balance, adding MgO will not affect the balance.
IV) Removing SO3 will decrease its concentration and therefore the reaction equilibrium will shift to the left.
Answer:
Group 13
Explanation:
We have been given some properties of the elements we desire to identify.
The most important and by far unique is the oxidation state of the ions given. This reflects the amount of electrons an atom has lost or gained.
Group 1 and 2 elements have oxidation states of +1 and +2 respectively. This is a very perculiar property of these metals. When group 1 elements lose an electron, nobility is achieved and this goes for group 2 elements too.
Group 12 consists of transition elements. Most transition elements are known to have variable oxidation states. In this group, the common oxidation state is +2.
Group 13 elements have two dominant oxidation numbers which are +1 and +3. Particularly, Aluminum has +2 oxidation state too.
The properties fits in well for aluminum which is a group 13 element.
Answer:
i think this would be an example of a physical change because here the substance is changing directly from a solid to a gas without passing through the liquid state which means that the composition of the substance has not changed and remains the same. This is also called sublimation.
Answer:
-2
Explanation:
Consider object is starting 12 units right from the reference point which is 0.
Assign the right direction positive sign.
when object is moving 14 units on left direction the position of object will be two units to the left side of reference point.
Assign the left direction negative sign position will be -2.
