Answer:
That is the membrane of the cell
Explanation:
The cell membrane is made up of layers of protein and fat. It is made with a <em>phospholipid bilayer</em>. It allows some substances to pass into the cell while blocking others. This is known as <em>semipermeability</em>.
Answer:
Stars which never disappear below the horizon are called <u>circumpolar</u> stars.
Answer:
destroyed, from, endothermic
Explanation:
Energy is conserved in chemical reactions. It is neither created nor destroyed but can be transferred from one form to another.
An exothermic reaction transfers energy from the reacting substance to the surroundings. The body of the container feels warm. An exothermic reaction has a negative value of enthalpy.
An endothermic reaction transfers energy from the surroundings to the reacting substance. The body of the container feels cold. In an endothermic reaction, enthalpy is positive.
The benzoic acid Collect the top layer dry with Na2SO4 and evaporate the solvent.
Benzoic acid is sparingly soluble in water and forms a precipitate. The benzoic acid can then be separated by suction filtration through a Buchner funnel. Washing with sodium bicarbonate converts the benzoic acid to the more water-soluble form of sodium benzoate, which is extracted into the aqueous layer. Additionally, sodium bicarbonate neutralizes the catalytic acid in this reaction.
Benzoic acid containing the naphthalene impurity can be purified by crystallization in water. The reaction between benzoic acid and NaOH is an acid-base neutralization reaction. An acid reacts with a base to form salt and water. In aqueous solutions, NaOH increases the solubility of benzoic acid. Benzoic acid cannot move from one layer to another because ethanol is immiscible with water.
Learn more about Benzoic acid here:-brainly.com/question/28299797
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Molar mass:
Ca(OH)₂ = 74.093 g/mol
Ca₃(PO₄)₂ = 310.17 g/mol
Mole ratio:
<span>2 Na</span>₃<span>PO</span>₄<span> + 3 Ca(OH)</span>₂<span> = Ca</span>₃<span>(PO</span>₄<span>)</span>₂<span> + 6 NaOH
</span>
3 x 74.093 g Ca(OH)₂ ----------- 310.17 g Ca₃(PO₄)₂
?? g Ca(OH)₂ ----------- 3.09 g Ca₃(PO₄)₂
Mass of Ca(OH)₂ = 3.09 x 3 x 74.093 / 310.17
Mas of Ca(OH)₂ = 686.84211 / 310.17
= 2.214 g of Ca(OH)₂
hope this helps!
