The molecular weight of a substance is calculated by adding the molecular mass of each element present in the molecule multiplied by the number of times each element is in the molecule. For greater clarity, we can organize a table that allows us to do the calculations. We have the following structure for water:
The molecular weight of water will be:
2.01568 + 15.999 = 18.0468=18.0 g/mol
Answer= 18.0
This problem is providing the mass of both magnesium metal and oxygen gas and involved in a chemical reaction and asks for the limiting reactant. At the end, it turns out to be identified as magnesium.
<h3>Stoichiometry</h3>
In chemistry, stoichiometry is a widely-used tool we use in order to relate the mass and moles of different chemical substances involved in a chemical reaction. Thus, we consider the following chemical equation between magnesium and oxygen to produce magnesium oxide.
However, when the mass of the both of the reactants is given, one must identify the limiting reactant as the one producing the least of the moles of the product, which means we can use the given grams of the both of the reactants, their molar masses and mole ratios with the product to obtain the aforementioned:
Thus, we can evidence how 24 g of magnesium produce the least of the moles of magnesium oxide, fact validating the magnesium as the limiting reactant and the oxygen as the excess one.
Learn more about stoichiometry: brainly.com/question/9743981
Answer:
The solution's new volume is 1.68 L
Explanation:
Dilution is the procedure to prepare a less concentrated solution from a more concentrated one, and simply consists of adding more solvent. So, in a dilution the amount of solute does not vary, but the volume of the solvent varies.
In summary, a dilution is a lower concentration solution than the original.
The way to do the calculations in a dilution is through the expression:
Ci*Vi=Cf*Vf
where C and V are concentration and volume, respectively; and the i and f subscripts indicate initial and final respectively.
In this case, being:
- Ci= 7 M
- Vi= 0.60 L
- Cf= 2.5 M
- Vf=?
Replacing:
7 M*0.60 L= 2.5 M* Vf
Solving:
Vf= 1.68 L
<u><em>The solution's new volume is 1.68 L</em></u>
<u>Given:</u>
Initial temperature, T1 = 20 C
Final temperature, T2 = 40 C
<u>To determine:</u>
The temperature change
<u>Explanation:</u>
Convert degree C to Kelvin
Temperature in Kelvin = degree C + 273
T1 = 20 + 273 = 293 K
T2 = 40 + 273 = 313 K
Incremental temperature change = T2 - T1 = 313-293 = 20 K
Ans: The temperature change in kelvin is 20 K