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2 years ago

Label the following changes as Physical or

Chemistry

1 answer:

Leno4ka [110]2 years ago

5 0

Answer:

Two clear liquids mix and form a

white solid

18.chemical

A pot of water begins to

boil

19.Physical

the rest im usure on.

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Are any other answer correct ? ♈❤️

riadik2000 [5.3K]

Those two are correct, your just missing A.

6 0

2 years ago

Read 2 more answers

Carbon-14 (14C) dating assumes that the carbon dioxide on the Earth today has the same radioactive content as it did centuries a

Nataly [62]

<u>Answer:</u> The tree was burned 16846.4 years ago to make the ancient charcoal

<u>Explanation:</u>

The equation used to calculate rate constant from given half life for first order kinetics:

$t_{1/2}=\frac{0.693}{k}$

where,

$t_{1/2}$ = half life of the reaction = 5715 years

Putting values in above equation, we get:

$k=\frac{0.693}{5715yrs}=1.21\times 10^{-4}yrs^{-1}$

Rate law expression for first order kinetics is given by the equation:

$k=\frac{2.303}{t}\log\frac{[A_o]}{[A]}$

where,

k = rate constant = $1.21\times 10^{-4}yr^{-1}$

t = time taken for decay process = ? yr

$[A_o]$ = initial amount of the sample = 100 grams

[A] = amount left after decay process = 13 grams

Putting values in above equation, we get:

$1.21\times 10^{-4}=\frac{2.303}{t}\log\frac{100}{13}\\\\t=16864.4yrs$

Hence, the tree was burned 16846.4 years ago to make the ancient charcoal

8 0

2 years ago

What is the formula for titanium (I) dichromate?

MaRussiya [10]

The answer is TI(Cr207)2

8 0

2 years ago

Carbon diselenide (CSe2) is a liquid at room temperature. The normal boiling point is 125°C, and the melting point is –45.5°C. C

Tema [17]

Answer:

Explanation: The strengths of the inter molecular forces varies as follows -

$CO_{2}< CS_{2} < CSe_{2}$

The normal boiling point of CSe2 is 125°C and that of CS2 is 116°C, which explains the trend that as we move down the group, the boiling point of e compound increases as the size increases.

This usually happens because larger and heavier atoms have a tendency to exhibit greater inter molecular strengths due to the increase in size . As the size increases, the valence shell electrons move far away from the nucleus, thus has a greater tendency to attract the temporary dipoles.

And larger the inter molecular forces, more tightly the electrons will be held to each other and thus more thermal energy would be required to break the bonds between them.

5 0

3 years ago

A sample of methane gas has a volume of 10 l at a pressure of 1.5 atm and a temperature of 20 °c. what volume does the gas occup

a_sh-v [17]

We can use combined gas laws to solve for the volume of the gas
$\frac{PV}{T}$
where P - pressure, V - volume , T - temperature and k - constant
$\frac{P1V1}{T1} = \frac{P2V2}{T2}$
parameters for the first instance are on the left side and parameters for the second instance are on the right side of the equation
T1 - temperature in Kelvin - 20 °C + 273 = 293 K
T2 - 40 °C + 273 = 313 K
substituting the values
$\frac{1.5 atm*10L}{293 K} = \frac{0.9 atm*V}{313K}$
V = 17.8 L
volume of the gas is 17.8 L

7 0

3 years ago