A) 2H₂(g) + O₂(g) → 2H₂O(l) + 285.83 kJ
Exothermic
B) 2Mg + O₂ → 2MgO + 1200kJ
Exothermic
Answer:
1.07 g Ba
Explanation:
Hello there!
In this case, according to the definition of the Avogadro's number and the molar mass, it is possible to say that 6.022x10^{23} atoms of barium equal one mole, and at the same time, 1 mole equals 137.327 grams of this element; thus, it is possible to say that 6.022x10^{23} atoms of barium have a mass of 137.327 grams; therefore, it i possible for us to calculate the required mass in grams as shown below:

Best regards!
<span>Lithium has a property
of high reactivity and to obtain lithium is through electrolysis of its fused
salts. Because lithium is very reactive, it is not found free so electrolysis
is use to split it apart to get it. Moreover,
Lithium is an alkali metal with single valence electron that is easily given up
to form cation, which make it a good conductor of heat and electricity.</span>
<span> </span>
1. H₂SO₄ + 2NH₄OH ⟶ (NH₄)₂SO₄ + 2H₂O
2. 2NaOH + H₂CO₃ ⟶ Na₂CO₃ + 2H₂O
3. HNO₃ + KOH ⟶ KNO₃ + H₂O
<em>Explanation</em>:
Acid + base ⟶ salt + water
Take the H from the acid and the OH from the base to get water.
Then, join what’s left to get the salt. Write the symbol for the metal first.
For example, in equation 3, take the H from HNO₃ and the OH from KOH.
Combining the remaining parts (NO₃ and K) to get the salt, KNO₃.
<u>Answer: </u>The volume of the solution is 85.7 mL
<u>Explanation:</u>
Molarity is defined as the amount of solute expressed in the number of moles present per liter of solution. The units of molarity are mol/L. The formula used to calculate molarity:
.....(1)
We are given:
Molarity of solution = 0.600 M
Given mass of
= 12.00 g
We know, molar mass of ![BaSO_4=[(1\times 137.33)+(1\times 32.07)+(4\times 16)]=233.4g/mol](https://tex.z-dn.net/?f=BaSO_4%3D%5B%281%5Ctimes%20137.33%29%2B%281%5Ctimes%2032.07%29%2B%284%5Ctimes%2016%29%5D%3D233.4g%2Fmol)
Putting values in equation 1, we get:

The rule of significant number that is applied for the problems having multiplication and division:
The least number of significant figures in any number of the problem determines the number of significant figures in the answer.
Here, the least number of significant figures is 3 that is determined by the number, 0.600. Thus, the answer must have these many significant figures only.
Hence, the volume of the solution is 85.7 mL