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3 years ago

6

The total number of each element is not changed during a chemical reaction

1 answer:

Paha777 [63]3 years ago

3 0

false all element when they are combined eachother thier valance number will change

the combination of oxygen and aluminum gives us Al2O3 see even the numbers are changing thank you if you have a comment you can write

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If an object has a volume of 2 millimeters and a mass of 10 grams, calculate the density of the object. (4 points)

kow [346]

Density = g/mL

10 g / 2 mL = 5 g/mL

3 0

3 years ago

A gas cylinder contains 2.5 atm of ne, 0.8 atm of co2, and 3.4 atm of ar. what is the total pressure in the cylinder? g

Tatiana [17]

To answer this problem, we must make assumptions for simplicity. The first assumption is that, the system only consist of these 3 gases. The second assumption is that, these gases behave ideally. Thus, from Dalton's Law of Partial Pressure, the total pressure is simply the sum of their individual partial pressures.

Total pressure = 2.5 + 0.8 + 3.4 = <em>6.7 atm</em>

6 0

3 years ago

anyanavicka [17]

I believe this a PV = nRT question whereas

you re write the formula and solve for volume

V = nRT/ P

then you input the values

P= pressure constant

V= x

n = moles = 0.2540

R = gas constant should be 8.314J mol

T = C degrees + 273.15 = K

solve for voume

make sure all units match

and use sig figs!!!!

7 0

3 years ago

During a titration the following data were collected. A 50.0 mL portion of an HCl solution was titrated with 0.500 M NaOH; 200.

Travka [436]

<u>Answer:</u> The mass of HCl present in 500 mL of acid solution is 36.5 grams

<u>Explanation:</u>

To calculate the concentration 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 HCl

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

We are given:

$n_1=1\\M_1=?M\\V_1=50.00mL\\n_2=1\\M_2=0.500M\\V_2=200.mL$

Putting values in above equation, we get:

$1\times M_1\times 50.00=1\times 0.500\times 200\\\\M_1=\frac{1\times 0.500\times 200}{1\times 50.00}=2M$

To calculate the mass of solute, we use the equation used to calculate the molarity of solution:

$\text{Molarity of the solution}=\frac{\text{Mass of solute}\times 1000}{\text{Molar mass of solute}\times \text{Volume of solution (in mL)}}$

Molar mass of HCl = 36.5 g/mol

Molarity of solution = 2 M

Volume of solution = 500 mL

Putting values in above equation, we get:

$2mol/L=\frac{\text{Mass of solute}\times 1000}{36.5g/mol\times 500}\\\\\text{Mass of solute}=\frac{2\times 36.5\times 500}{1000}=36.5g$

Hence, the mass of HCl present in 500 mL of acid solution is 36.5 grams

4 0

3 years ago

What structure do all of these elements have in common?

Dmitrij [34]

The answer is c because of going left to right

7 0

3 years ago

Read 2 more answers