Answer:
0.062 moles of hydrogen gas
Explanation:
We must first out down the reaction equation before we can attempt to solve the problem.
Mg(s) + 2HCl(aq) ----> MgCl2(aq) + H2(g)
Next we obtain the number of moles in 1.5 g of magnesium metal from;
Molar mass of magnesium = 24.3 gmol-1
Number of moles of magnesium= mass/molar mass = 1.5g/24.3gmol-1 = 0.062 moles
From the reaction equation;
1 mole of magnesium metal yields 1 mole of hydrogen gas
0.062 moles of magnesium metal will yield 0.062 moles of hydrogen gas
Therefore, reaction of 1.5g of magnesium metal with excess hydrochloric acid will yield 0.062 moles of hydrogen gas.
Answer: Index fossils are used to identify layers of rocks. The layers will form an arrangement that relates to their age. In simpler terms, a layer that contains fossils are unique to that certain layer.
Index fossils are fossils that are mostly used by scientists due to it being easily found anywhere around the world and in abundant amounts. It can also be easily identified since they are fossils of widely varied organisms that lived during one short time period.
A is correct (ur welcome)
Answer:
A & B
Explanation:
Leucine and phenylalanine have hydrophobic side chains, which means that they can interact with valine in the pocket. All other aminoacids on the list have polar (two electrically charged) side chains and cannot form hydrophobic pockets.
The correct answers are:
Trematodes are acoelomates that have effective defenses against attack by their hosts' immune system.
Trematodes are flatworms, internal parasites known as flukes. Their life cycle is complex: they sexually reproduce in vertebrates and asexual reproduce in mollusks (mostly snail). The body of flukes is covered with tough tegument that defends them form digestive enzymes of host’s intestine.
Cnidarians are diploblasts that produce complex, capsule-like organelles.
Cnidaria are water organisms with simple structure: two layers of epithelium and a jelly substance between them. The cells of Cnidaria-cnidocytes contain capsule with venom substance in it with protective role.
