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3 years ago

Science questions down below

Chemistry

1 answer:

goldenfox [79]3 years ago

4 0

Answer to first is outer covering, second is bacteria are single celled

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Four liquids are described in the table below. Use the second column of the table to explain the order of their freezing points,

KIM [24]

Transcribed image text: Four liquids are described in the table below. Use the second column of the table to explain the order of their freezing points, and the third column to explain the order of their boiling points. For example, select '1' in the second column next to the liquid with the lowest freezing point. Select '2' in the second column next to the liquid with the next higher freezing point, and so on. In the third column, select '1' next to the liquid with the lowest boiling point, '2' next to the liquid with the next higher boiling point, and so on. Note: the density of water is 1.00g/mL .

7 0

2 years ago

How many moles of oxygen must be placed

Annette [7]

0.24 moles of oxygen must be placed in a 3.00 L container to exert a pressure of 2.00 atm at 25.0°C.

The variables given are Pressure, volume and temperature.

Explanation:

Given:

P = 2 atm

V = 3 litres

T = 25 degrees or 298.15 K by using the formula 25 + 273.17 = K

R = 0.082057 L atm/ mole K

n (number of moles) = ?

The equation used is of Ideal Gas law:

PV = nRT

n = $\frac{PV}{RT}$

Putting the values given for oxygen gas in the Ideal gas equation, we get

n = $\frac{2 x 3}{0.082157 x 298.15}$

= 0.24

Thus, from the calculation using Ideal Gas law it is found that 0.24 moles of oxygen must be placed in a container.

Ideal gas law equation is used as it tells the relation between temperature, pressure and volume of the gas.

3 0

3 years ago

Read 2 more answers

How many ml of 0.5M of HNO3 would be needed to react with 85ml of 0.75M of KOH

olganol [36]

Answer: 127.5ml

Explanation:

To calculate the volume of acid, we use the equation given by neutralization reaction:

$n_1M_1V_1=n_2M_2V_2$

where,

$n_1,M_1\text{ and }V_1$ are the n-factor, molarity and volume of acid which is $HNO_3$

$n_2,M_2\text{ and }V_2$ are the n-factor, molarity and volume of base which is KOH.

We are given:

$n_1=1\\M_1=0.5M\\V_1=?mL\\n_2=1\\M_2=0.75M\\V_2=85mL$

Putting values in above equation, we get:

$1\times 0.5\times V_1=1\times 0.75\times 85\\\\V_1=127.5mL$

Thus 127.5 ml of 0.5M of HNO3 would be needed to react with 85ml of 0.75M of KOH

6 0

3 years ago

why is whenever one raised to the power of any exponent 1 and why is 0 raised to the power of any exponent 1

IceJOKER [234]

When you use exponents, think of it like this. 1 squared is 1 x 1. 1 cubed is 1 x 1 x 1. And 1 to the power of 4 is 1 x 1 x 1 x 1. And so on. You basically just multiply them by themselves. 0 to the power of any exponent is 1, well that's just a rule. It doesn't make much sense but it's easy to remember and I wouldn't worry about it.

5 0

2 years ago

A 32.8 g sample of gas occupies 22.414 L at STP. What is the molecular weight of this gas?

olasank [31]

Answer:

32.8g/mole

Explanation:

Given parameters:

Mass of sample of gas = 32.8g

Volume = 22.4L

Unknown:

Molecular weight = ?

Solution:

To solve this problem we must understand that at rtp;

1 mole of gas occupies a volume of 22.4L

Number of mole of the gas = 1 mole

Now;

Mass = number of moles x molecular weight

molecular weight = $\frac{mass}{molecular weight}$ = $\frac{32.8g}{1mole }$ = 32.8g/mole

8 0

2 years ago