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3 years ago

At STP, which 2.0-gram sample of matter uniformly fills a 340-milliliter closed container?

Chemistry

1 answer:

Xelga [282]3 years ago

6 0

Answer;

D, Xe (g)

Solution and explanation;

If 2g has a volume of 340ml.

Density is 1000/340*2 = 5.88g/litre.

-This rules out the two solids, choices 2) &3)

If 1 litre has mass 5.88g,

then 22.4 liters (volume at STP) has mass 5.88*22.4 = 131.8g/mol

molar mass Br2 = 80*2 = 160g/mol NO

molar mass Xe = 131.3g/mol = YES.

Answer is Xe

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Which part of the flower produces seeds? (992 points)

Nata [24]

Answer:

The pistil, B.

Explanation:

The seeds are formed from the ovule which is contained in the ovary; all in the base, the pistil.

5 0

2 years ago

Air containing 0.04% carbon dioxide is pumped into a room whose volume is 6000 ft3. The air is pumped in at a rate of 2000 ft3/m

koban [17]

Here is the full question:

Air containing 0.04% carbon dioxide is pumped into a room whose volume is 6000 ft3. The air is pumped in at a rate of 2000 ft3/min, and the circulated air is then pumped out at the same rate. If there is an initial concentration of 0.2% carbon dioxide, determine the subsequent amount in the room at any time.

What is the concentration at 10 minutes? (Round your answer to three decimal places.

Answer:

0.046 %

Explanation:

The rate-in;

$R_{in}$ $= \frac{0.04}{100}*2000$

$R_{in}$ = 0.8

The rate-out

$R_{out}$ = $\frac{A}{6000}*2000$

$R_{out}$ = $\frac{A}{3}$

We can say that:

$\frac{dA}{dt}=$ $0.8-\frac{A}{3}$

where;

A(0)= 0.2% × 6000

A(0)= 0.002 × 6000

A(0)= 12

$\frac{dA}{dt} +\frac{A}{3} =0.8$

Integration of the above linear equation =

$e^{\int\limits \frac {1}{3}dt } =$ $e^{\frac{1}{3}t$

so we have:

$e^{\frac{1}{3}t}\frac{dA}{dt}} +\frac{1}{3}e^{\frac{1}{3}t}A$ $= 0.8e^{\frac{1}{3}t$

$\frac{d}{dt}[e^{\frac{1}{3}t}A]$ $= 0.8e^{\frac{1}{3}t$

$Ae^{\frac{1}{3}t} =2.4e\frac{1}{3}t +C$

∴ $A(t) = 2.4 +Ce^{-\frac{1}{3}t$

Since A(0) = 12

Then;

$12 =2.4 + Ce^{-\frac{1}{3}}(0)$

$C= 12-2.4$

$C =9.6$

Hence;

$A(t) = 2.4 +9.6e^{-\frac{t}{3}}$

$A(0) = 2.4 +9.6e^{-\frac{10}{3}}$

$A(t) = 2.74$

∴ the concentration at 10 minutes is ;

= $\frac{2.74}{6000}*100$ %

= 0.0456667 %

= 0.046% to three decimal places

7 0

3 years ago

Popeye wants to make a dilute spinach solution for Sweetpea's bottle. How much 3.0 M spinach solution should he add to the 500.0

Lynna [10]

Answer : The volume of 3.0 M spinach solution added should be, 50 mL

Explanation :

Formula used :

$M_1V_1=M_2V_2$

where,

$M_1\text{ and }V_1$ are the initial molarity and volume of spinach solution.

$M_2\text{ and }V_2$ are the final molarity and volume of diluted spinach solution.

We are given:

$M_1=3.0M\\V_1=?\\M_2=0.30M\\V_2=500.0mL$

Now put all the given values in above equation, we get:

$3.0M\times V_1=0.30M\times 500.0mL\\\\V_1=50mL$

Hence, the volume of 3.0 M spinach solution added should be, 50 mL

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3 years ago

Naturally occurring neon exists as three isotopes. 90.51% is ne-20 with a mass of 19.99 amu, 0.27% is ne-21 with a mass of 20.99

gregori [183]

The atomic mass of an element is the average relative mass of its atoms as compared with an atom of carbon-12 whose mass is taken as 12. In terms of percentages of different isotopes, the average atomic mass can be determined as follows: $A_{average}$ = ∑( $p_{i}$ X $A_{i}$ )/100. Where, $p_{i}$ is the percentage abundance of isotope with atomic number $A_{i}$ .

So, average atomic mass of neon = $\frac{(90.51 X 19.99) + (0.27 X 20.99) + (9.22 X 21.99)}{100}$ = 20.177 amu.

3 0

3 years ago

The word elliptical refers to what type of shape?

Ilya [14]

The word elliptical refers to an Oval.

7 0

3 years ago

Read 2 more answers