The best and most correct answer among the choices provided by your question is the first choice or letter A "<span>The chemical bonds of the products have more energy than the chemical bonds of the reactants."
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The term endothermic<span> process describes a process or </span>reaction<span> in which the system absorbs energy from its surroundings; usually, but not always, in the form of heat.</span>
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Answer:
= 67.79 g
Explanation:
The equation for the reaction is;
4Cr(s)+3O2(g)→2Cr2O3(s)
The mass of O2 is 21.4 g, therefore, we find the number of moles of O2;
moles O2 = 21.4 g / 32 g/mol
=0.669 moles
Using mole ratio, we get the moles of Cr2O3;
moles Cr2O3 = 0.669 x 2/3
=0.446 moles
but molar mass of Cr2O3 is 151.99 g/mol
Hence,
The mass Cr2O3 = 0.446 mol x 151.99 g/mol
<u> = 67.79 g
</u>
99.9224 % of the acid is not ionized.
____HA + H₂O ⇌ A⁻ + H₃O⁺
I: ___<em>c</em> ________0 ____0
C: _-α<em>c</em> _______+α<em>c</em> __+α<em>c
</em>
E: <em>c</em>(1-α) _______α<em>c</em> ___α<em>c
</em>
pH = 4.110
[H₃O⁺] = α<em>c</em> = 10^(-4.110) mol/L = 7.76 × 10⁻⁵ mol/L
α = 7.76 × 10⁻⁵
1 – α = 1 - 7.76 × 10⁻⁵ = 0.999 224 = 99.9224 %
Temperature. Water is an example. When water is at room temp. its liquid. When water is at boiling temp. It is a gas. And when water is at freezing temp. Its a solid.
Part 1)
Cu- <span>[Ar] 3d¹⁰4s¹ </span><span>atomic number: 29
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<span>O- [He] 2s2 2p<span>4 atomic number:8
</span></span>La- <span>[Xe] 5d¹ 6s² </span><span>atomic number:57
Y- </span><span>[Kr] 4d¹5s² </span><span>atomic number:39
Ba- </span><span>[Xe] 6s² </span><span>atomic number:56
Tl- </span><span>[Xe] 4f¹⁴ 5d¹⁰ 6s² 6p¹ </span><span>atomic number:81
Bi- </span> <span>[Xe] 4f¹⁴ 5d¹⁰ 6s² 6p³ </span>atomic number:83
Part 2)
You are able to this by consulting the periodic table and following this steps:
-Find your atom's atomic number;
<span>-Determine the charge of the atom (these were all uncharged)
</span><span>-Memorize the order of orbitals (s, d, p, d.. and how many electrons they can fit)
</span>-<span>Fill in the orbitals according to the number of electrons in the atom
- </span><span>for long electron configurations, abbreviate with the noble gases</span>
