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%
Answer:
45 neutrons
Explanation:
Bromine has 35 protons and a mass number of 80. a) How many neutrons does the atom of bromine have? The mass number = protons + neutrons. Bromine has a mass number of 80 and 35 protons so 80-35 = 45 neutrons.
Answer:5-3=2
As 5apple eaten 3apple so left 2apple
Answer:17.955atm
Explanation:Pv=nrt
P= nrt/v
P= 7.25*0.08205*360/11.90
P= 214.1505/11.90
P=17.995atm
Answer:
B. first level consumers.
Explanation:
The first level consumers are also the primary consumers. They are the animals that depends or rely on plants to transform chemical energy into carbohydrates and sugar.
Primary consumers are mostly herbivores. They feed on plant matter by which they derive their nutrition. They have special enzymes that helps to convert plant materials into substances needed for their body.
So, the first level consumer takes plant matter and convert them into useful food materials for their own nutrition.
The second level consumers depend on the first level consumers for nutrition.
