The correct answer for this question would be option B. The common name of the group whose members are characterized by endoskeleton and a unique water vascular system are called the <span> Echinoderms. Examples of echinoderms are starfish, sea urchin, feather stars and sea cucumbers. Hope this is the answer that you are looking for.</span>
Answer:
1= 2H₂ + O₂ → 2H₂O
2=CaCo₃ + heat → CaO +CO₂
3=CH₄ + 2O₂ → CO₂ +2H₂O
4=HCl + NaOH → NaCl + H₂O
Explanation:
1 = Simple composition
The formation of water molecule is simple composition reaction. In this reaction two hydrogen atoms react with one oxygen atom and form one water molecules.
2H₂ + O₂ → 2H₂O
The amount of energy released is -285.83 KJ/mol. It is exothermic reaction.
2 = Simple decomposition reaction:
The break down of sodium hydrogen carbonate into sodium carbonate, carbondioxide and water is decomposition reaction. The decomposition reactions re mostly endothermic, because compound required energy to break.
2NaHCO₃ + heat → Na₂CO₃ + H₂O + CO₂
It is endothermic reaction.
Another example is:
CaCo₃ + heat → CaO +CO₂
3 = Combustion reaction
Consider the combustion of methane:
CH₄ + 2O₂ → CO₂ +2H₂O
The burning of methane is exothermic. The combustion reactions are exothermic because when fuel are burns they gives energy.
4 = Neutralization reaction
The neutralization reactions are those in which acid and base react to form the salt and the water. Some neutralization reactions are exothermic because they release heat. e.g
Consider the neutralization reaction of HCl and NaOH.
HCl + NaOH → NaCl + H₂O
If the density is higher than water than the object will sink
Answer:
0.022 mol O
Explanation:
Mg3(Si2O5)2(OH)2
We can see that 1 mol of this substance has 3 mol of Mg.
Oxygen altogether is 5*2 (from (Si2O5)2) + 2(from(OH)2) = 10 +2 = 12
So, 1 mol of this substance has 12 mol oxygen.
So, 1 mol of this substance contains 3 mol Mg and 12 mol O, or
ratio Mg : O = 3 : 12 = 1 : 4
1 mol Mg ----- 4 mol O
0.055 mol Mg ---x mol O
x = 0.055*4/1 = 0.220 mol O
Using P1V1/T1 = P2V2/T2, 1 being the conditions initially and 2 being the secondary conditions…. always make sure you convert you units first , L=695.8262L
