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3 years ago

Write the number of sig. fig. in four numbers given in the sentence below. An (one) octopus has 8 legs. 13 octopi have 104 legs.

Chemistry

1 answer:

Marrrta [24]3 years ago

6 0

Answer:

1, 1, 2, 3

Explanation:

The numbers 1 and 8 both have 1 sig. fig.

The number 13 has 2 sig. figs.

The number 104 has 3 sig. figs.

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Heating 2.40 g of the oxide of metal X (molar mass of X = 55.9 g/mol) in carbon monoxide (CO) yields the pure metal and carbon d

Korolek [52]

Answer:The molecular formula of the oxide of metal be $X_2O_3$ . The balanced equation for the reaction is given by:

$X_2O_3+3CO\rightarrow 3CO_2+2X$

Explanation:

Let the molecular formula of the oxide of metal be $X_2O_y$

$X_2O_y+yCO\rightarrrow yCO_2+2X$

Mass of metal product = 1.68 g

Moles of metal X = $\frac{1.68 g}{55.9 g/mol}=0.03005 mol$

1 mol of metal oxide produces 2 moles of metal X.

Then 0.03005 moles of metal X will be produced by:

$\frac{1}{2}\times 0.03005 mol=0.01502 mol$ of metal oxide

Mass of 0.01502 mol of metal oxide = 2.40 g (given)

$0.01502 mol\times (2\times 55.9 g/mol+y\times 16 g/mol)=2.40 g$

y = 2.999 ≈ 3

The molecular formula of the oxide of metal be $X_2O_3$ . The balanced equation for the reaction is given by:

$X_2O_3+3CO\rightarrow 3CO_2+2X$

8 0

3 years ago

Complete the equation to show how hydrofluoric acid, HF, acts as a Brønsted-Lowry acid in water. Balanced equation:

shepuryov [24]

Answer : The balanced equation is,

$HF+H_2O\rightleftharpoons H_3O^++F^-$

Explanation :

According to the Bronsted Lowry concept, Bronsted Lowry-acid is a substance that donates one or more hydrogen ion in a reaction and Bronsted Lowry-base is a substance that accepts one or more hydrogen ion in a reaction.

The balanced chemical reaction will be,

$HF+H_2O\rightleftharpoons H_3O^++F^-$

In this reaction, hydrofluoric acid is act as a Bronsted Lowry-acid because it donate one hydrogen ion to $H_2O$ and $H_3O^+$ is act as a Bronsted Lowry-base because it accept one hydrogen ion from $HF$ .

8 0

4 years ago

Thủy phân este trong môi trường kiềm, thu được natri axetat và ancol metylic. công thức X là gì?

ValentinkaMS [17]

Correct option is B ethyl ethanoate

The following compound is ester R−COO−R ′ and the naming of ester are done on the basis of alkanoate group (R−COO−) and alkyl (R ′ ) combined to form ester.The suffix for ester is "-oate". The full name of ester is like alkyl alkanoate. Thus the name of given compound is ethyl ethanoate.

- BRAINLIEST answerer ❤️

3 0

3 years ago

How are electric circuits like water in pipes list two ways

____ [38]

They flow through the inslation of the house .

they both help things travel

8 0

3 years ago

The heat capacity of water is 1cal degree'g1 (1 calorie per degree centigrade, per gram). You are given 1 gallon of water at 25

sdas [7]

Answer:

The heat needed to boil 1 gallon of water is 81,490.62 Joules.

Explanation:

$Q=mc\Delta T$

Where:

Q = heat absorbed or heat lost

c = specific heat of substance

m = Mass of the substance

ΔT = change in temperature of the substance

We have :

Volume of water = V = 1 gal = 4546.09 mL

Density of water , d= 1 g/mL

mass of water = m = d × V = 1g/mL × 4546.09 mL = 4546.09 g

Specific heat of water = c = 1 Cal/g°C

ΔT = 100°C - 25°C = 75 °C

9 (boiling pint of water is 100°C)

Heat absorbed by the water to make it boil:

$Q= 4546.09 g\times 1 Cal/g^oC\times 75^oC=340,956.75 Cal$

1 calorie = 4.184 J

$Q=\frac{340,956.75}{4.184} J = 81,490.62 J$

The heat needed to boil 1 gallon of water is 81,490.62 Joules.

5 0

3 years ago