Answer:
D. all of these
Explanation:
In the classification of organisms, they are placed into groups which they appropriately fit into.
All the choices given correctly shows the process of classifying organisms. This aspect of biology is described as taxonomy.
- Based on characteristics of organisms, they are put into the same groups
- Also, we can identify the related family and genus in which a discovered organism can be put into.
- They phylogenetic relationship between organisms are important for classification.
6.069 grams is the mass of hydrogen formed when 27 g of aluminum reacts with excess hydrochloric acid.
Explanation:
Balanced equation for the reaction:
2 Al + 6 HCl → 2 AlCl₃ + 3 H₂
data given:
mass of aluminum = 27 grams
atomic mass of one mole of aluminum = 26.89 grams/mole
formula to calculate number of moles:
number of moles = 
number of moles = 
= 1.004 moles of aluminum will react
from the balanced equation:
2 moles of Al reacted to form 3 moles of H2
1.004 moles of Al will produce x moles of H2
= 
x = 3.012 moles of H2 will be formed.
mass will be calculated as number of moles multiplied by atomic weight
mass of 3.012 moles of hydrogen ?(atomic weight of one mole H2 = 2.015 grams)
= 3.012 x 2.015
= 6.069 grams of H2 will be formed.
Answer:
A Winter storm usually does not come with a warm fronthey warm front.
Explanation:
When the front passes over an area it means to change in the weather. Many. Many friends cause weather events such as rain thunderstorms gusty winds tornadoes and hurricanes.
Answer:
ΔH = -55.92 kJ
Explanation:
<u>Step 1:</u> Data given
1 mol NaOH and 1 mol HBr initially at 22.5 °C are mixed in 100g of water
After mixing the temperature rises to 83 °C
Specific heat of the solution = 4.184 J/g °C
Molar mass of NaOH = 40 G/mol
Molar mass of HBr = 80.9 g/mol
<u>Step 2: </u>The balanced equation
NaOH + HBr → Na+(aq) + Br-(aq) + H2O(l)
<u>Step 3:</u> mass of NaOH
Mass = moles * Molar mass
Mass NaOH = 1 * 40 g/mol
Mass NaOH = 40 grams
Step 4: Mass of HBr
Mass HBr = 1 mol * 80.9 g/mol
Mass HBr = 80.9 grams
Step 5: Calculate ΔH
ΔH = m*c*ΔT
ΔH= (100 + 40 + 80.9) * 4.184 * (83-22.5)
ΔH= 220.9 * 4.184 * 60.5
ΔH= 55916.86 J = 55.92 kJ
Since this is an exothermic reaction, the change in enthalpy is negative.
ΔH = -55.92 kJ
