Answer: Option (1) is the correct answer.
Explanation:
Compounds are the substances which contain two or more different elements.
Similarly, water is a compound as it is made up when two hydrogen atoms combine with one oxygen atom. Compounds can be broken down with the help of chemical reactions.
Hence, the statement water can be broken down by chemical means explains why water is classified as a compound.
Ultrasound is sound or vibrations, having an ultrasonic frequency, particularly as used in medical imaging. Ultrasound is more commonly used in medical terminology than in industry. Infrasound is sound waves with frequencies below the lower limit of human audibility.
<h2> The correct option is (a).</h2>
Explanation:
- There is no change of state in pouring water into a vacuum insulated bottle as the vacuum created inside the bottle only reduces the time limit for the transfer of heat by conduction and convection.
- It helps the content filled in the bottle to be hot and cool for a longer time.
Hence, option (a) is correct.
Rest of the options (b), (c), (d), (e) is not correct because of the following reasons:
- In the sublimation of dry ice, the dry ice (solid-state) is changed to the vapour form.
- In the freezing of water, the liquid state is changed to solid-state.
- During the vaporization of alcohol, the liquid state is changed to the vapour form.
- During the melting of ice, the solid-state is changed to the liquid state.
Answer: C(s) + O2(g) --> CO2(g)12g (C) .... 50.8g (O2)................. initial amounts0g(C) .........18.8g(O2) ................. amounts when reaction completeThat means that C was the limiting reactant, and the amount of CO2 is based on the amount of carbon that burned. Covert 12 grams of carbon to moles. The moles of CO2 will be the same, since they are in a 1:1 mole ratio. Then convert the moles of CO2 to grams.12g C x (1 mol C / 12.0 g C) x (1 mol CO2 / 1 mol C) x (44.0g CO2 / 1 mol CO2) =44 g of CO2
