Answer:
The process of making S'more by adding chocolate bar, gram-crackers, and marshmallows in layers is not a chemical reaction
Explanation:
In a chemical reaction, the substances involved in the reaction are known as the reactants and the substances produced have different physical and chemical properties than those of the reactants and they are known as the products.
The bonds that hold the atoms of the reactants are broken down and rearranged, creating entirely new substances as products. Therefore, energy must be added and/or evolved in any chemical reaction and all reactant atoms should be involved in the reaction.
The change in energy can be sensed as heat change such as increase or decrease in the temperature of the products
Since S'more does not involve any of the above changes that occur in a chemical reaction when the chocolate bar, gram-crackers, and marshmallows are put together, it is not a chemical change or a chemical reaction.
Describe the process by which Ag+ ions are precipitated out of solution. 4. In your testing, several precipitates are formed, and then dissolved as complexes.
Answer:
Percentage yield = 85.2%
Explanation:
Given data:
Mass of Mg = 21.3 g
Actual yield of MgO = 30.2 g
Percentage yield = ?
Solution:
Chemical equation:
2Mg + O₂ → 2MgO
Number of moles of Mg = mass/molar mass
Number of moles of Mg = 21.3 g / 24.3 g/mol
Number of moles of Mg = 0.88 mol
Now we will compare the moles of MgO with Mg.
Mg : MgO
2 : 2
0.88 : 0.88
Mass of MgO:
Mass of MgO= moles × molar mass
Mass of MgO= 0.88 mol × 40.3g/mol
Mass of MgO = 35.46 g
Actual yield of MgO = 30.2 g
Percentage yield:
Percentage yield = Actual yield/theoretical yield × 100
Percentage yield = 30.2 g/ 35.46 g × 100
Percentage yield = 85.2%
The formula mass of a molecule is the sum of the atomic weights of the atoms in the empirical formula of the compound. It is also known as Formula Weight.
The atomic weights of
N = 14.01 amu
H = 1.00 amu
P = 30.97 amu
O = 16.0 amu
Now, we will calculate now the formula mass of a given substance
3(14.01) + 12(1.00) + 1(30.97) + 4(16.0) = 42.03 + 12.00 + 30.97 + 64.0 = 149.0 amu
Therefore, the formula mass for (NH4)3PO4 is 149.0 amu
