What is the percent composition by mass of oxygen in magnesium oxide, MgO?
Answer: 39.7 percent
Answer:
chemical reactions which proceed with the release of heat energy are called exothermic reactions
Answer:
High melting point,High density,Nonreactive
Explanation:
The following are the Properties of transition elements:
They have large charge/radius ratio. They are harder and they have high densities;.They have high melting and boiling points.They form compounds which are paramagnetic. They show variable oxidation states. They form colored ions and compounds. Compounds are formed with profound catalytic activity. Stable complexes are formed by them.
When Comparing with the alkali metals present in group 1 and the alkaline Earth metals that are present in group 2, the transition metals are considered to be much less reactive. They do not react fast with water or oxygen, which contributes to their resistance to corrosion.
First we need to find the number of moles that 43.9g of gallium metal is. We can do this by finding the molar weight of gallium and cross-multiplying to cancel out units:

So we are dealing with 0.63 moles of gallium metal.
We can take from the balanced equation that 4 moles of gallium metal will react completely with 3 moles of oxygen gas. We can take this ratio and make a proportion to find the amount of oxygen gas, in moles, that will react completely with 0.63 moles of gallium metal:

Cross multiply and solve for x:


So now we know that 0.47 moles of oxygen gas will react with 43.9g of gallium metal.
Mass of iron chloride (FeCl₂) : 22.68 g
<h3>Further explanation</h3>
Proust stated the Comparative Law that compounds are formed from elements with the same Mass Comparison so that the compound has a fixed composition of elements
In the same compound, although from different sources and formed by different processes, it will still have the same composition/comparison
With this law, we can calculate how many grams an element is needed to make a compound with a certain mass, as desired
<h3 />

The iron ions in 50 g mixture :

