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2 years ago

Which statement is true with respect to an atom?

2 answers:

7 0

The atomic number of an atom is equal to the number of protons.

The atomic number represents the equal number of protons and electrons in an element.

Elena-2011 [213]2 years ago

6 0

The atomic number represents the equal number of protons and electrons in an element. Hope i helped

Cheers,
Belive1234

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Consider the incorrectly balanced combustion equation:

Ulleksa [173]

Oxygen is balanced incorrectly.
The correct balanced equation: 2C6H6+15O2=12CO2+6H2O

6 0

2 years ago

How many grams of lithium sulfide (Li2S) are in 275 g of a 16 % aqueous solution of Li2S?

krok68 [10]

Answer:

600 mAh·g−1

Explanation:

i hope this is good let me know if its wrong

3 0

2 years ago

A sample of oxalic acid (a diprotic acid of the formula H2C2O4) is dissolved in enough water to make 1.00 L of solution. A 100.0

OleMash [197]

Answer: The mass of original oxalic acid sample is 6.75 grams

Explanation:

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 $H_2C_2O_4$

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

We are given:

$n_1=2\\M_1=?M\\V_1=100.0mL\\n_2=1\\M_2=0.750M\\V_2=20.0mL$

Putting values in above equation, we get:

$2\times M_1\times 100.0=1\times 0.750\times 20.0\\\\M_1=\frac{1\times 0.750\times 20.0}{2\times 100.0}=0.075M$

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

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

Given mass of oxalic acid = ? g

Molar mass of oxalic acid = 90 g/mol

Molarity of solution = 0.075 M

Volume of solution = 1.00 L

Putting values in above equation, we get:

$0.075M=\frac{\text{Mass of oxalic acid}}{90g/mol\times 1L}\\\\\text{Mass of oxalic acid}=(0.075\times 90\times 1)=6.75g$

Hence, the mass of original oxalic acid sample is 6.75 grams

7 0

2 years ago

The graph above plots gravitational force versus distance for two asteroids of equal mass (10 billion kg). When the distance bet

natima [27]

Answer:ABOUT 74 N

Explanation: TOOK THE TEST ON STUDY ISLAND :)

7 0

2 years ago

Read 2 more answers

450g of chromium(iii) sulfate reacts with excess potassium phosphate. How many grams of potassium sulfate will be produced? (ANS

Irina18 [472]

Answer:

600 g K₂SO₄

Explanation:

First write down the complete, balanced chemical equation for such question. In this case:

Cr₂(SO₄)₃ + 2K₃PO₄ → 3K₂SO₄ + 2CrPO₄

Next, calculate molar masses of required compounds mentioned in the question. In this case it is for Cr₂(SO₄)₃ and K₂SO₄.

Molar mass(MM) of Cr₂(SO₄)₃:

= 2*(MM of Cr) + 3*( MM of S) + 3*4*( MM of O)

= 2*(52) + 3*(32) + 12*(16)

= 104 + 96 + 192

= 392 g

Molar mass(MM) of K₂SO₄:

= 2*(MM of K) + 1*( MM of S) + 4*( MM of O)

= 2*(39) + 32 + 4*(16)

= 78 + 32 + 64

= 174 g

Here comes the concept of Limiting reagent:

The limiting reagent in a chemical reaction is the substance that is totally consumed when the chemical reaction is complete. The amount of product formed is limited by this reagent, since the reaction cannot continue without it. The other reactants present with this are usually in excess and called excess reactants. If quantities of both the reactants are given, then one should apply unitary method and find out the limiting reagent out of the two. Then, determine the amount of product formed or percentage yield.

Also, 1 mole( 392 g) of Cr₂(SO₄)₃ gives 3 moles( 174*3 = 522 g) of K₂SO₄.

Using unitary method, if 392g of Cr₂(SO₄)₃ gives 522 g of K₂SO₄ , then 450 g of Cr₂(SO₄)₃ will give how much of K₂SO₄?

Yeild of K₂SO₄ : $\frac{522 * 450}{392}$

That is 599.3 g.

Since we have not considered molecular masses of individual atoms to 6 decimal places, this number can be approximated to 600g.

Therefore, 600g of K₂SO₄ is produced.

6 0

3 years ago