Rubber.
Iron, copper, and graphite are minerals. Rubber is not a mineral.
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your answer is b hope this helps
Answer:
⇒ We have Na2O + H2O --> NaOH. We have 2 sodiums and 2 oxygens and 2 hydrogens on the left side, but only one of each on the right side.
Sodium Oxide + Water → Sodium Hydroxide
⇒ Na2O + H2O → 2NaOH .
Sodium oxide is used in ceramics and glasses. Sodium oxide reacts exothermically with cold water to produce sodium hydroxide solution.
Answer is: hydrogen peroxide <span>is more hazardous to consume.
</span>Median lethal dose<span>, </span><span>LD50</span><span> (</span>lethal dose, 50%) <span>is a measure of the </span>lethal dose<span> of a </span>toxin. LD50<span> used as a general indicator of a substance's </span>acute toxicity, lower LD50<span> is indicative of increased toxicity (in this case </span>900 mg/kg is lower than <span>3310 mg/kg).</span>
Ca(OH)2(aq) + 2HCl(aq)------> CaCl2(aq) + 2H2O(l) ΔH-?
CaO(s) + 2HCl(aq)-----> CaCl2(aq) + H2O(l), Δ<span>H = -186 kJ
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CaO(s) + H2O(l) -----> Ca(OH)2(s), Δ<span>H = -65.1 kJ
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1) Ca(OH)2 should be reactant, so
CaO(s) + H2O(l) -----> Ca(OH)2(s)
we are going to take as
Ca(OH)2(s)---->CaO(s) + H2O(l), and ΔH = 65.1 kJ
2) Add 2 following equations
Ca(OH)2(s)---->CaO(s) + H2O(l), and ΔH = 65.1 kJ
<span><u>CaO(s) + 2HCl(aq)-----> CaCl2(aq) + H2O(l), and ΔH = -186 kJ</u>
</span>Ca(OH)2(s)+CaO(s) + 2HCl(aq)--->CaO(s) + H2O(l)+CaCl2(aq) + H2O(l)
Ca(OH)2(s)+ 2HCl(aq)---> H2O(l)+CaCl2(aq) + H2O(l)
By addig these 2 equation, we got the equation that we are needed,
so to find enthalpy of the reaction, we need to add enthalpies of reactions we added.
ΔH=65.1 - 186 ≈ -121 kJ
