Answer:
9.1 mg/dL
Explanation:
A normal distribution is symmetrical, the area below the curve of negative Z-scores is equal to the area below the curve of positive Z-scores, Z measures the statistic observed and the parameter of the population.
And it is:
Z = (x - μ)/σ
where μ is the mean (9.5 mg/dL), x is the borderline, and σ is the standard deviation, which is 0.3 mg/dL.
The Z-score can be calculated in excel by the function =NORMSINV, and the factor will be the percente considered (10% = 0.1)
NORMSINV(0.1) = -1.28155
So,
-1.28155 = (x - 9.5)/0.3
x - 9.5 = -0.384465
x = 9.1 mg/dL
Answer: 0.771 g of 
will be produced
Explanation:
To calculate the moles :
The balanced chemical reaction is:
According to stoichiometry :
2 moles of 
produce = 3 moles of
Thus 0.257 moles of will produce=
of
Mass of 
Thus 0.771 g of will be produced
1 mol of Silicon = 28.0855 g (in average)
then
1 mol = 6.022*10^23 atoms
then
28.0855/(6.022*10^23) g/atom
4.66381*10^-23 g per atom
Answer:
chemical energy is stored in the wood before combustion.
Answer:
Fe₂O₃ and C are reactants
Fe and CO₂ are products
Explanation:
Reactants:
Chemical species that are present on left side of chemical reaction equation are called reactants.
Product:
Chemical species that are present on right side of chemical reaction equation are called product.
Chemical equation:
2Fe₂O₃ + 3C → 4Fe + 3CO₂
In this reaction 2 mole of iron oxide is react with three moles of carbon and produced four moles of iron and three moles of carbon dioxide. There are equal numbers of atoms of all elements present on both side of chemical reaction so this reaction follow the law of conservation of mass.
Law of conservation of mass:
According to the law of conservation mass, mass can neither be created nor destroyed in a chemical equation.
Explanation:
This law was given by french chemist Antoine Lavoisier in 1789. According to this law mass of reactant and mass of product must be equal, because masses are not created or destroyed in a chemical reaction.
