Answer:
Chemical indicator, any substance that gives a visible sign, usually by a colour change, of the presence or absence of a threshold concentration of a chemical species, such as an acid or an alkali in a solution. An example is the substance called methyl yellow, which imparts a yellow colour to an alkaline solution.
Explanation:
Answer:
Explanation:
Given reaction
N₂H₄ + O₂ ⇒ N₂ + 2H₂O ΔH₁ = -543 KJ ---------- ( 1 )
2H₂ + O₂ ⇒ 2H₂O ΔH₂ = -484 KJ ---------- ( 2 )
N₂ + 3 H₂ ⇒ 2NH₃ ΔH₃ = -92 KJ -----------( 3 )
( 1 ) - ( 2 ) +( 3 )
N₂H₄ + O₂ - 2H₂ - O₂ +N₂ + 3 H₂ ⇒ N₂ + 2H₂O - 2H₂O +2NH₃
ΔH = -543 + 484 -92 = -151 KJ
N₂H₄ + H₂ ⇒ 2NH₃ ΔH = -151 KJ .
2NH₃ ⇒ N₂H₄ + H₂ ΔH = + 151 KJ
Your mom :)
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Answer:
There are two chloride ions for each calcium ion
Explanation:
The compound has to have an overall neutral charge. Meaning that the positive charges from calcium have to be canceled out by the negative charges of chlorine.
If there are two chloride ions for each calcium ion, the charges would cancel themselves out (2 * -1 would cancel out with +2).
Answer:
A or C
really i think it is both can you pick more than one or no
