C. A new substance is produced. All others are physical changes.
Answer:
Mass = 357.7 g
Explanation:
Given data:
Mass of Fe = 250 g
Mass of oxygen = 120 g
Mass of iron(III) oxide produced = ?
Solution:
Chemical equation:
4Fe + 3O₂ → 2Fe₂O₃
Number of moles of Fe:
Number of moles = mass/molar mass
Number of moles = 250 g/ 55.8 g/mol
Number of moles = 4.48 mol
Number of moles of O₂ :
Number of moles = mass/molar mass
Number of moles = 120 g/ 32 g/mol
Number of moles = 3.75 mol
Now we will compare the moles of reactants with product.
Fe : Fe₂O₃
4 : 2
4.48 : 2/4×4.48 = 2.24
O₂ : Fe₂O₃
3 : 2
3.75 : 2/3×3.75= 2.5
Less number of moles of Fe₂O₃ are produced by Fe thus it will act as limiting reactant.
Mass of Fe₂O₃:
Mass = number of moles × molar mass
Mass = 2.24 mol × 159.69 g/mol
Mass = 357.7 g
Given the following choices, determine which best suits as a characteristic of a hurricane.
Answer Choices:
A. Hurricanes occur mostly inland
B. Hurricanes create widespread damage
C. Hurricanes can only last for a short amount of time
D. Hurricanes gain strength after passing overland
Best Answer: B. Hurricanes can create widespread damage.
Reason: A would not be correct since it is more of a variable, due to the fact that hurricanes usually begin near the coastlines, hurricanes are in fact capable of moving inland for atleast 100 miles before it dies down to a tropical storm or depression.
C is not correct since hurricanes can last up to a whole week which is approximately 168 hours.
D is not correct since it is another variable in which hurricanes can decrease in strength if it comes into contact with cool and dry air which is the opposite of warm and moist which it needs in order to occur.
Therefore, the best choice is B. Hurricanes can create widespread damage, hurricanes can unleash a staggering arsenal of mother nature's strength and the most damage a hurricane has caused can go up to 125 billion USD in damages.
Answer:
B.Convection
the movement caused within a fluid by the tendency of hotter and therefore less dense material to rise, and colder, denser material to sink under the influence of gravity, which consequently results in transfer of heat.
The two ways to measure the sand in a sand castle are by counting the number of pails of sand used to build the castle and by determining the mass of the sand used in building the castle. The first method makes use of the volume of the pail to determine the amount of sand while the second method is a more quantitative way.<span />
