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2 years ago

Which of the following is an example of a physical change?

Chemistry

2 answers:

o-na [289]2 years ago

7 0

Answer:

I think b is the correct answer

just olya [345]2 years ago

4 0

Answer:evaporation in a swamp cooler

Explanation:

Evaporation in a swamp cooler simply involves the conversion of water in the liquid state to water in the gaseous state. It is an easily reversible process if the vapour can be collected and condensed. A chemical change involves the formation of a new substance and is not easily reversible. It is a chemical reaction. A dry cell operates by a chemical change which produces voltage in the cell. Digestion involves a series of irreversible chemical reactions catalysed by enzymes. Hence the answer.

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Which of the following is a correct inference that one can make about the burning of gasoline?

nikitadnepr [17]

Well first we can say that B. and D. are out BC they are physical changes we are looking for chemical changes when burning gas, the gas is burning and converting into heat energy AKA FIRE!!!. so the answer is indeed (A. <span>Chemical bonds are broken and others are formed.)
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<span />BTW im not a girl every one ask that. the girls in the pic is my GF
any ways i hope you can learn something new from this. :) <3 have any amazing day

3 0

2 years ago

Read 2 more answers

Consider the following reaction where K. = 154 at 298 K: 2NO(g) + Brz(9) 2NOBr(g) A reaction mixture was found to contain 2.69x1

bekas [8.4K]

Explanation:

$2NO(g) + Br_2(g)\rightleftharpoons 2NOBr(g)$

Equilibrium constant of reaction = $K=154$

Concentration of NO = $[NO]=\frac{2.69\times 10^{-2} mol}{1 L}=2.69\times 10^{-2} M$

Concentration of bromine gas = $[Br_2]=\frac{3.85\times 10^{-2} mol}{1 L}=3.85\times 10^{-2} M$

Concentration of NOBr gas = $[Br_2]=\frac{9.56\times 10^{-2} mol}{1 L}=9.56\times 10^{-2} M$

The reaction quotient is given as:

$Q=\frac{[NOBr]^2}{[NO]^2[Br_2]}=\frac{(9.56\times 10^{-2} M)^2}{(2.69\times 10^{-2} M)^2\times 3.85\times 10^{-2} M}$

$Q=328.06$

$Q>K$

The reaction will go in backward direction in order to achieve an equilibrium state.

1. In order to reach equilibrium NOBr (g) must be produced. False

2. In order to reach equilibrium K must decrease. False

3. In order to reach equilibrium NO must be produced. True

4. Q. is less than K . False

5. The reaction is at equilibrium. No further reaction will occur. False

8 0

2 years ago

Diethyl ether is produced from ethanol according to the following equation:

juin [17]

The balanced chemical equation is given as:

2CH3CH2OH(l) → CH3CH2OCH2CH3(l) + H2O(l)

We are given the yield of CH3CH2OCH2CH3 and the amount of ethanol to be used for the reaction. These values will be the starting point for the calculations.

Theoretical amount of product produced:
329 g CH3CH2OH ( 1 mol / 46.07 g ) ( 1 mol CH3CH2OCH2CH3 / 2 mol CH3CH2OH ) (74.12 g / mol ) = 264.66 g CH3CH2OCH2CH3

% yield = .775 = actual yield / 264.66

actual yield = 205.11 g CH3CH2OCH2CH3

6 0

2 years ago

How much positive charge is in 0.7 kg of lithium? with each atom having 3 protons and 3 electrons. The elemental charge is 1.602

hichkok12 [17]

Explanation:

As a neutral lithium atom contains 3 protons and its elemental charge is given as $1.602 \times 10^{-19} C$ . Hence, we will calculate its number of moles as follows.