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2 years ago

Identify the following examples as either physical or chemical change.

Chemistry

1 answer:

Natalka [10]2 years ago

6 0

Answer:

19. Physical

20. Physical

21. Chemical

22. Physical

23. Chemical

24. Chemical

25. Physical

Explanation:

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Why do we use scientific notation or scientific exponential numbers in math calculations?

seraphim [82]

I believe the answer is: in order not to write very big or very small number values

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2 years ago

calculate the difference in slope of the chemical potential against temperature on either side of the normal freezing point of w

kipiarov [429]

Answer:

(a) The normal freezing point of water (J·K−1·mol−1) is $-22Jmole^-^1k^-^1$

(b) The normal boiling point of water (J·K−1·mol−1) is $-109Jmole^-^1K^-^1$

(c) the chemical potential of water supercooled to −5.0°C exceed that of ice at that temperature is 109J/mole

Explanation:

Lets calculate

(a) - General equation -

$(\frac{d\mu(\beta )}{dt})p-(\frac{d\mu(\alpha) }{dt})_p$ = $-5_m(\beta )+5_m(\alpha )$ = $-\frac{\Delta H}{T}$

$\alpha ,\beta$ → phases

ΔH → enthalpy of transition

T → temperature transition

$(\frac{d\mu(l)}{dT})_p -(\frac{d\mu(s)}{dT})_p$ = $= -\frac{\Delta_fH}{T_f}$

= $\frac{-6.008kJ/mole}{273.15K}$ ( $\Delta_fH$ is the enthalpy of fusion of water)

= $-22Jmole^-^1k^-^1$

(b) $(\frac{d\mu(g)}{dT})_p-(\frac{d\mu(l)}{dT})_p= -\frac{\Delta_v_a_p_o_u_rH}{T_v_a_p_o_u_r}$

= $\frac{40.656kJ/mole}{373.15K}$ ( $\Delta_v_a_p_o_u_rH$ is the enthalpy of vaporization)

= $-109Jmole^-^1K^-^1$

$[\mu(l-5$ ° $C)-\mu(l,0$ ° $C)]$ = $[\mu(s-5$ ° $C)-\mu(s,0$ ° $C)]$ $=-S_m$ ΔT

$\mu(l,-5$ ° $C)-\mu(s,-5$ ° $C)=-Sm\DeltaT [\mu(l,0$

$\Delta\mu=(21.995Jmole^-^1K^-^1)\times (-5K)$

= 109J/mole

6 0

1 year ago

PLEASE HELP MEEEEEEEEEEEEEEEEEEEEEEE

Genrish500 [490]

Answer:

Liquid

Explanation:

Gas is too far away, solid is close but it is not in a random pattern

4 0

2 years ago

Read 2 more answers

How do you write a chemical equation given a word equation ? (Chemistry)

earnstyle [38]

Step one: Identify reactants and products and place them in a word equation.

Step two: Convert the chemical names into chemical formulas. Place them based on the chemical equation and write the state symbols.

Step three: balance the chemical equation.

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2 years ago

Pre-lab questions 1. a concentration gradient affects the direction that solutes diffuse. describe how molecules move with respe

VLD [36.1K]

Just like how heat moves from a region of higher temperature to a region of lower temperature, molecules also tend to move from a region of higher concentration to a region of lower concentration. This is called natural diffusion and is naturally happening to reach stability.

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2 years ago