Answer:
H₂(g) + Cl₂(g) → 2HCl(g) + 185kJ
Explanation:
In a chemical reaction, enthalpy of reaction ΔH is a thermodynamic constant that gives information if the reaction is exothermic (Produce heat if reacts) or endothermic (Consume heat if reacts).
In the reaction:
H₂(g) + Cl₂(g) → 2HCl(g) ΔH = -185kJ
As ΔH <0, the reaction is exothermic, that means, <em>produce heat</em>, writing a balanced thermochemical equation:
<em>H₂(g) + Cl₂(g) → 2HCl(g) + 185kJ</em>
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The enthalpy is as a product beacause an exothermic reaction produces heat.
I hope it helps!
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Answer:
B) 2
Explanation:
Significant figures : The figures in a number which express the value -the magnitude of a quantity to a specific degree of accuracy is known as significant digits.
The rule apply for the multiplication and division is :
The least number of significant figures in any number of the problem determines the number of significant figures in the answer.
The rule apply for the addition and subtraction is :
The least precise number present after the decimal point determines the number of significant figures in the answer.
(3.478-2.31) = 1.168 ≅ 1.17 (Rounded to least decimal digit)
(4.428-3.56) = 0.868 ≅ 0.87 (Rounded to least decimal digit)
So,
1.17 * 0.87 = 1.0 (Rounded to least significant)
Answer - two significant digits
Take the attached picture of a periodic table as a guide. You are finding for a solid metal. Therefore, streamline your choices by looking at elements written in black bold letters, because they are all solid. Next, if you look at the center, the legend for metals are colors in orange, yellow, flesh, lavender, pink, and cyan blue. These region would be your choices. Next, you want to find a metal that is shiny and ductile. The shiny appearance is a common characteristic of luster by materials. Ductility is the ability of a metal to stretch when under tensile stress. These properties are best exhibited by metals in the transitions metals colored in pink. Therefore, the answer to your question would be any of the metal in the pink area. Examples are Titanium, Chromium, Gold, Silver, Platinum, Tungsten, etc.
Answer : The formula for each of the following is:
(a) 
(b) 
(c) 
Explanation :
- Alkanes are hydrocarbon in which the carbon atoms are connected with single covalent bonds.
The general formula of alkanes is
where n is the number of the carbon atoms present in a molecule of alkane.
- Alkenes are hydrocarbon in which the carbon atoms are connected with double covalent bonds.
The general formula of alkenes is
where n is the number of the carbon atoms present in a molecule of alkene.
- Alkynes are hydrocarbon in which the carbon atoms are connected with triple covalent bonds.
The general formula of alkynes is
where n is the number of the carbon atoms present in a molecule of alkyne.
(a) An alkane with 22 carbon atoms
Putting n = 22 in the general formula of alkane, we get the formula of alkane as,
or 
(b) An alkene with 17 carbon atoms
Putting n = 17 in the general formula of alkene, we get the formula of alkene as,
or 
(c) An alkyne with 13 carbon atoms
Putting n = 13 in the general formula of alkyne, we get the formula of alkyne as,
or 