Answer:
a. True
Explanation:
Alkanes are chains of carbon atoms surrounded by hydrogen atoms. TRUE.
Alkanes are hydrocarbons, that is, they are organic compounds formed only by carbon and hydrogen. In alkanes, carbon atoms are bonded to each other through single covalent bonds and they are also bonded to hydrogen atoms through the same type of bonds. Alkanes have the general formula CnH2n+2.
Answer: Undecane, C11H24 is a liquid hydrocarbon from the alkane homologue ( family ).
Explanation:
All hydrocarbons burn in air to release H20 and CO2.
Combustion of hydrocarbons thus increases the percentage of CO2 present in the atmosphere which is not so good as CO2 is a greenhouse gas. Greenhouse gases produce the greenhouse effect. The green house effect is the warming effect produced when gases present in the atmosphere allow and retain the radiation from the sun to the earth. Examples of greenhouse gases are CO2, CH4, SO3, NO, CFCs. The greenhouse effect leads to an increase in the temperature of the earth subsequently leading to (I) melting of large amounts of ice at the poles causing flooding. (II) rapid evaporation of water from Earth’s surface. (III) decrease in crop yield.
Also, high concentration CFCs ( chlorofluorocarbons ), as widely used in aerosols, coolants and packaging foams, in the atmosphere depletes the ozone layer leading to global warming. In 1996 an international agreement was reached for a complete ban of CFCs and more countries are now going Green ( using alternative energy sources ) so as to minimize emissions of these greenhouse gases
The SI unit for amount<span> of </span>substance<span> is the </span>mole<span>. It has the unit symbol mol. The proportionality constant is the inverse of the Avogadro constant. The </span>mole<span> is defined as the </span>amount<span> of </span>substance that contains<span> an equal </span>number<span> of elementary entities as there are </span>atoms in 12g<span> of the </span>isotope<span> carbon-</span>12<span>.
Hope This Helped! :3</span>
Helium has the smallest atomic radius® Α⇒Ω
Answer:
She can add 380 g of salt to 1 L of hot water (75 °C) and stir until all the salt dissolves. Then, she can carefully cool the solution to room temperature.
Explanation:
A supersaturated solution contains more salt than it can normally hold at a given temperature.
A saturated solution at 25 °C contains 360 g of salt per litre, and water at 70 °C can hold more salt.
Yasmin can dissolve 380 g of salt in 1 L of water at 70 °C. Then she can carefully cool the solution to 25 °C, and she will have a supersaturated solution.
B and D are wrong. The most salt that will dissolve at 25 °C is 360 g. She will have a saturated solution.
C is wrong. Only 356 g of salt will dissolve at 5 °C, so that's what Yasmin will have in her solution at 25 °C. She will have a dilute solution.
