<h3><u>Answer;</u></h3>
C. 3Mg + Al2O3 → 3MgO + 2Al
<h3><u>Explanation;</u></h3>
- <u><em>Single replacement reaction is a type of reaction which one reactant reacts with another and makes a product by replacing one element by another. </em></u>
- Mg (Magnesium) reacts with Al₂O₃ (Aluminium oxide) and produces MgO (Magnesium oxide) and Al (Aluminium) as products. Here Al is replaced by Mg. Reaction is
Mg + Al₂O₃ → MgO + Al
- To balance the reaction equation, both left and right hand sides should have same number of atoms in each element.
The balanced equation will be;
3Mg + Al2O3 → 3MgO + 2Al
Percent error is [(abs(experimental - actual))/(actual)] * 100
(38.0 - 40.0 ) / 40.0 = 2.0 / 40 = 0.05
0.05 * 100 = 5
since there are 2 sigfigs, the answer is 5.0 %
I made the 2 positive since the absolute value of 38.0 - 40.0 was taken
There are only 2 sigfigs because of the subtraction of 38.0 - 40.0 gives 2.0, only 2 sigfigs
Answer:
A) He is in a cold area.
Explanation:
I dont know it is just normal for your hairs to do that in the cold weather.
Explanation:
The balanced equation of the reaction is given as;
Mg(OH)2 (s) + 2 HBr (aq) → MgBr2 (aq) + 2 H2O (l)
1. How many grams of MgBr2 will be produced from 18.3 grams of HBr?
From the reaction;
2 mol of HBr produces 1 mol of MgBr2
Converting to masses using;
Mass = Number of moles * Molar mass
Molar mass of HBr = 80.91 g/mol
Molar mass of MgBr2 = 184.113 g/mol
This means;
(2 * 80.91 = 161.82g) of HBr produces (1 * 184.113 = 184.113g) MgBr2
18.3g would produce x
161.82 = 184.113
18.3 = x
x = (184.113 * 18.3 ) / 161.82 = 20.8 g
2. How many moles of H2O will be produced from 18.3 grams of HBr?
Converting the mass to mol;
Number of moles = Mass / Molar mass = 18.3 / 80.91 = 0.226 mol
From the reaction;
2 mol of HBr produces 2 mol of H2O
0.226 mol would produce x
2 =2
0.226 = x
x = 0.226 * 2 / 2 = 0.226 mol
3. How many grams of Mg(OH)2 are needed to completely react with 18.3 grams of HBr?
From the reaction;
2 mol of HBr reacts with 1 mol of Mg(OH)2
18.3g of HBr = 0.226 mol
2 = 1
0.226 = x
x = 0.226 * 1 /2
x = 0.113 mol
Moles = mass / molar mass
<span>moles P = 0.422 g / 30.97 g/mol = 0.01363 mol </span>
<span>moles O = (0.967 g - 0.422g) / 16.00 g/mol = 0.03406 moles </span>
<span>So ratio moles P : moles O </span>
<span>= 0.01363 mol : 0.03406 mol </span>
<span>Divide each number in the ratio by the smallest number </span>
<span>(0.01363 / 0.01363) : (0.03406 / 0.01363) </span>
<span>= 1 : 2.5 </span>
<span>The empirical formula needs to be the smallest whole number ratio of atoms in the molecules. Since you have a non-whole number, multiply the ratio by the smallest number needed to make both number whole numbers. In this case x 2 </span>
<span>2 x (1 : 2.5) </span>
<span>= 2 : 5 </span>
