Answer:
1) CO₂
2) 0.2551 g
Explanation:
The balanced reactions are:
CaCO₃ + 2HCl → CaCl₂ + H₂O + CO₂
MgCO₃ + 2HCl → MgCl₂ + H₂O + CO₂
1) The gas produced is CO₂.
2) Calculate mass of CaCO₃:
(0.5236 g) (0.4230) = 0.2215 g CaCO₃
Convert to moles:
(0.2215 g CaCO₃) (1 mol / 100.1 g) = 0.002213 mol CaCO₃
Find moles of CaCO₃:
(0.002213 mol CaCO₃) (1 mol CO₂ / mol CaCO₃) = 0.002213 mol CO₂
Convert to mass:
(0.002213 mol CO₂) (44.01 g / mol) = 0.09738 g CO₂
Calculate mass of MgCO₃:
(0.5236 g) (0.5770) = 0.3021 g MgCO₃
Convert to moles:
(0.3021 g MgCO₃) (1 mol / 84.31 g) = 0.003583 mol MgCO₃
Find moles of MgCO₃:
(0.003583 mol MgCO₃) (1 mol CO₂ / mol MgCO₃) = 0.003583 mol CO₂
Convert to mass:
(0.003583 mol CO₂) (44.01 g / mol) = 0.1577 g CO₂
Total mass of CO₂:
0.09738 g CO₂ + 0.1577 g CO₂ = 0.2551 g CO₂
Answer:
C. Point B
Explanation:
The exposed curve represents a logistic growth model. Population growth depends on density. Natality and mortality depend on the population size, meaning that there is no independence between population growth and population density.
When a population grows in a limited space, density rises gradually and eventually affects the multiplication rate. The population per capita growth rate decreases as population size increases. The population reaches a maximum point delimited by available resources, such as food or space. This point is known as the carrying capacity, K.
K is a constant that equals population size at the equilibrium point, in which the natality and the mortality rate get qual to each other.
Referring to population size as N, when
- N<K, the population can still grow.
- N approximates to K, the population´s growth speed decreases.
- N=K the population reaches equilibrium,
- N>K, the population must decrease in size because there are not enough resources to maintain that size.
The sigmoid curve represents the logistic growth model.
- Point A: During this period, the population size is relatively stable. Little growth is expressed.
- Point B: At the beginning of this period, population growth increases softly. The more individuals are in the population, the more that reaches sexual maturity and get to reproduce, leaving fertile offspring. This fertile offspring also get to reproduce and leave more fertile individuals. At the end of the period, the curve shows a sharp slope, reflecting the significant increase in the population reproductive rate.
- Point C: At the beginning of this period, the population keeps on growing exponentially. But at the end of the period, the curve tends to stabilize, meaning that the population stops growing in size so fast. The population slow and gradually reaches the equilibrium point, K.
- Point D: The population got to stabilize.
Answer:
C. HMG-CoA reductase will be dephosphorylated
Explanation:
When a low density lipoprotein particle is taken up by the cell, the impact it will have on the regulation of de novo cholesterol synthesis will be HMG-CoA reductase being dephosphorylated.
HMG-CoA( 3-hydroxy-3-methyl-glutaryl-CoA reductase) is an enzyme which aids the synthesis of lipids. When the lipids are produced and taken up by the cells then the effect of the synthesis stops to avoid excess synthesis and to allow for the action of enzymes which will act ok them in the cells . This is why it leads to a dephosphorylation of the enzyme which stops the action.
The digestive process, inside the small intestine.
