Answer:
6. They all have the same number of molecules.
7. 19.5 g
Explanation:
6. From Avogadro's hypothesis, we understood that 1 mole of any substance contains 6.02×10²³ molecules i.e
1 mole = 6.02×10²³ molecules
Considering the question given above, each compounds has just 1 mole. Thus, they will also have the same number of molecules.
7. Determination of the mass of iron (Fe)
Number of mole of Fe = 0.35 mole
Molar mass of Fe = 55.85 g/mol
Mass of Fe =?
Mass = mole × molar mass
Mass of Fe = 0.35 × 55.85
Mass of Fe = 19.5 g
Thus, the mass of 0.35 mole of iron (Fe) is 19.5 g
Answer:
Mass percent of N2H4 in original gaseous mixture = 31.13 %
Explanation:
Given:
Initial mass of gaseous mixture = 61.00 g
Initial mole of oxygen = 10.0 mol
Moles of oxygen remaining after the reaction = 4.062 mol
Moles of oxygen used = 10.0 - 4.062 = 5.938 mol
Total oxygen used in both the reactions = 10.0 parts
out of 10 parts, 3 part react with N2H4.
Now, consider the reaction of N2H4
3 moles of O2 react with 1 mole of N2H4
1.78 moles of oxygen will react with 1.78/3 = 0.5933 mol of N2H4
Molecular mass of N2H4 = 32 g/mol
Total mass = 61.0 g
The mass percent of N2H4 in the gaseous mixture can be determined through stoichiometric calculations and determining the limiting reactant. The initial and remaining amounts of O2 are used to calculate the reacted amount of O2, which then allows for the calculation of the amount of N2H4. This information is used in the mass percent formula.
The balanced reaction states that for one mole of NH3, one mole of O2 is required, while for one mole of N2H4, 3 moles of O2 are required. Thus, the initial moles of O2 were 10 moles and after reaction 4.062 moles O2 remained. Thus, the reacted amount of O2 is 10 - 4.062 = 5.938 moles. From calculating the limiting reactant and applying stoichiometry, the amount of N2H4 can be determined. We know the molar mass of N2H4 is 32 g/mole. By calculating the molar ratio, we can then calculate the mass percent of N2H4 in the mixture using the formula: (mass of N2H4 / total mass) * 100%.
#SPJ12
Answer and explanation;
Coal has aromatic hydrocarbons with high molar mass and has a high ratio of carbon to hydrogen. Burning coal produces more soot than burning other fossil fuels does because of it.
Fossil fuel mixtures of hydrocarbons that formed from the remains of plants or animals. Burning fossil fuels increases the amount of carbon dioxide in the atmosphere. This increase may affect temperatures, amounts of rain and sea levels worldwide. Some sulfur and nitrogen are in fossil fuels, and air contains nitrogen.
Coal produces more soot than other fossil fuels as it is a carbon-rich fossil fuel, where some carbon atoms form soot particles during burning. The combustion of coal is less efficient, producing more particulates and carbon dioxide per unit energy output, thus contributing to air pollution and global warming.
Coal typically produces more soot than other fossil fuels when burned due to its composition. Unlike natural gas or oil, coal is a carbon-rich fossil fuel. When this carbon burns, it reacts with oxygen to form carbon dioxide, but not all carbon atoms complete this reaction. Some form tiny carbon particles or soot instead. These soot particles consist of amorphous carbon, which has a disorganized and complex structure, leading to the dark, dust-like quality of soot.
Historically, the burning of coal was ubiquitous in the Industrial Age, leading to severe air pollution with coal soot covering surfaces in industrial cities. This is because the combustion of coal is less efficient than other fossil fuels, producing more particulates and carbon dioxide per unit energy output. Consequently, the combustion of fossil fuels, and coal in particular, contributes to the greenhouse effect and global warming. In fact, coal-fired power plants produce the greatest amount of CO₂ per unit energy output compared to natural gas or oil, making it the least efficient fossil fuel in terms of greenhouse gas emissions.
#SPJ3
C₃H₈ + 5O₂ = 3 CO₂ + 4 H₂O
44.1 g ----------- 4* 18.02 g
? g --------------- 75 g
mass of C₃H₈ = 75 * 44.1 / 4 * 18.02
mass of C₃H₈ = 3307.5 / 72.08
= 45.886 g of propane
b. conservation of matter.
c. atomic disintegration.
d. definite proportions.
your answer is b. conservation of matter.
i just took the test
Answer: b. Conservation of matter.
Explanation:
Law of conservation of matter states that matter can neither be created nor destroyed by means of chemical reaction but can be changed from one form to another.
It means that the amount of matter remains the same after a chemical change.
Answer: 181 kJ
Explanation:
The balanced chemical reaction is;
To calculate the moles, we use the equation:
According to stoichiometry:
1 mole of on complete combustion give= 555 kJ
Thus 0.326 moles of on complete combustion give=
Thus the enthalpy change for combustion of 15.0 g of ethanol is 181 kJ
Answer:
Explanation:
The notation of the most common isotope of silicon is:
The superscript, 28, to the left of the chemical symbol, Si, is the mass number, usually identified with the symbol A, and it is the sum of the protons and neutrons.
The subscript, 14, to the left of the chemical symbolr, Si, is the atomic number, Z, which is the number of protons.
Then, you have this equation:
The number of protons is the same for any isotope of the same element. This is, all the isotopic forms of silicon have the same number of prtons: 14
The number of neutrons is determined from the equation A = Z + N, solving for N:
Hence, the most common isotope of silicon has 14 protons and 14 neutrons.