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Tomtit [17]
2 years ago
6

Brainliest will be given! Please help!

Chemistry
1 answer:
Marat540 [252]2 years ago
7 0
Use this formula to find it
amount \: left = starting \: amount \:  {( \frac{1}{2})}^{ \frac{time \: gone}{half \: life} }
Starting amount = 40g
Half life = 4 days
Time gone = 12 days
Amount left = 40 (1/2)^12/4
= 40 (1/2)^3
= 40 (1/8)
= 5 grams
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Compute the number of grams(g) of lead in 22.5 moles of lead.
iogann1982 [59]

Answer:

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Explanation:

hope this helps :).

7 0
2 years ago
In the following reaction, 451.4 g of lead reacts with excess oxygen forming 365.0 g of lead(II) oxide. Calculate the percent yi
user100 [1]
Let MM(x) be the molar mass of x.

MM(Pb) : MM(PbO)
=207.21 : 223.20  =  451.4 g : x g

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= 486.23 g

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4 0
3 years ago
Please help as soon and best answer gets brainlest
Ann [662]

Answer:

Mass, temperature, and phase.

I think temperature because the higher the temperature of a given quantity of a substance, more is its thermal energy. Similarly, for the same temperature, higher mass of a substance will contain more thermal energy.

5 0
2 years ago
A gas occupies a volume of 31.0 ml at 19.0°C. If the gas temperature rises to 38.0°C at constant pressure. Calculate the new vol
Alik [6]

Answer:

The correct answer is 0.0033 L (33.0 mL)

Explanation:

We uses the Charles's law which describes the changes in the volume (V) of a gas and its temperature in Kelvin (T) at constant pressure. The mathematical expression is the following:

V₁/T₁ = V₂/T₂

We have the following data:

V₁= 31.0 mL = 0.0031 L

T₁= 19.0°C = 292 K

T₂= 38.0°C = 311 K

V₂= ?

We calculate V₂ from the mathematical expression, as follows:

V₂= V₁/T₁ x T₂ = 0.0031 L/(292 K) x 311 K = 0.0033 L

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The answer is +1! Have a great day!
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