Alkanes are saturated hydrocarbon, that is they contain hydrogen and carbon without a double or triple bond between the carbon atoms, e.g. ethane, propane. Group 7a in the periodic table are called halogens e.g chlorine, bromine. Alkanes react with halogens in a reaction called substitution, where halogens replace hydrogen atoms in alkanes.
Answer:
preservation of raw materials
Explanation:
Reusing and recycling is the process by which the used products are used again or recycled in different form to use it again. Excessive use of the raw materials can lead to their extinction. Recycling the materials helps in decreasing the pollution in the environment. It also helps in reduction in the emission of the harmful gases. When municipal wastes are reused or recycled, the raw materials are preserved. These are the process involved in sustainable use of resources.
Answer:
a mixture of molecules - Box f
atoms of a pure elementa metal - Box D
a solid compound - Box C
a mixture of elements - Box A
Explanation:
Box a has mixture of elements which forms a solid like shape but there are different elements present in the box. The box f has mixture of molecules in which many atoms are combined together. Box c has solid compound with single element.
<span>There's a trend in electronegativity. The bottom left of periodic table is the lowest (0.7) and the upper right is the highest (4.0). The most polar is the greatest difference in electronegavity.
hbr- 1~ , hi- 0.5~ ,hcl - 1.3~ , hf-1.8 so,hf is the answer</span>
<span>Answer: 0.094%
</span><span>Explanation:
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1) Equilibrium chemical equation:
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<span>Only the ionization of the formic acid is the important part.
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<span>HCOOH(aq) ⇄ HCOO⁻(aq) + H⁺(aq).
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<span>2) Mass balance:
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<span> HCOOH(aq) HCOO⁻(aq) H⁺(aq).
Start 0.311 0.189
Reaction - x +x +x
Final 0.311 - x 0.189 + x x
3) Acid constant equation:
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<span>Ka = [HCOO-] [N+] / [HCOOH] = (0.189 + x) x / (0.311 -x)
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<span>= (0.189 + x )x / (0.311 - x) = 0.000177
4) Solve the equation:
You can solve it exactly (it will lead to a quadratic equation so you can use the quadratiic formula). I suggest to use the fact that x is much much smaller than 0.189 and 0.311.
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<span>With that approximation the equation to solve becomes:
</span><span>0.1890x / 0.311 = 0.000177, which leads to:</span>
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x = 0.000177 x 0.311 / 0.189 = 2.91 x 10⁻⁴ M
5) With that number, the percent of ionization (alfa) is:
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<span>percent of ionization = (moles ionized / initial moles) x 100 =
</span><span>
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</span><span>percent ionization = (concentration of ions / initial concentration) x 100 =
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</span><span>percent ionization = (0.000291 / 0.311)x 100 = 0.0936% = 0.094%
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