BALANCE THE EQUATION: C4H10 + O2 = CO2 + H2O

Why is water less dense as a solid than a liquid? In ecological terms, why is this of particular importance?

Georgia [21]

Persamaan setara pada reaksi besi dengan asam klorida membentuk besi (II) klorida dan gas hidrogen

3 0

2 years ago

How many moles of sodium carbonate are contained by 57.3g of sodium carbonate

Lady_Fox [76]

Answer:

$\boxed {\boxed {\sf 0.541 \ mol \ Na_2CO_3}}$

Explanation:

We are asked to find how many moles of sodium carbonate are in 57.3 grams of the substance.

Carbonate is CO₃ and has an oxidation number of -2. Sodium is Na and has an oxidation number of +1. There must be 2 moles of sodium so the charge of the sodium balances the charge of the carbonate. The formula is Na₂CO₃.

We will convert grams to moles using the molar mass or the mass of 1 mole of a substance. They are found on the Periodic Table as the atomic masses, but the units are grams per mole instead of atomic mass units. Look up the molar masses of the individual elements.

Na: 22.9897693 g/mol
C: 12.011 g/mol
O: 15.999 g/mol

Remember the formula contains subscripts. There are multiple moles of some elements in 1 mole of the compound. We multiply the element's molar mass by the subscript after it, then add everything together.

Na₂ = 22.9897693 * 2= 45.9795386 g/mol
O₃ = 15.999 * 3= 47.997 g/mol
Na₂CO₃= 45.9795386 + 12.011 + 47.997 =105.9875386 g/mol

We will convert using dimensional analysis. Set up a ratio using the molar mass.

$\frac {105.9875386 \ g \ Na_2CO_3}{1 \ mol \ Na_2CO_3}$

We are converting 57.3 grams to moles, so we multiply by this value.

$57.3 \ g \ Na_2CO_3} *\frac {105.9875386 \ g \ Na_2CO_3}{1 \ mol \ Na_2CO_3}$

Flip the ratio so the units of grams of sodium carbonate cancel.

$57.3 \ g \ Na_2CO_3} *\frac {1 \ mol \ Na_2CO_3}{105.9875386 \ g \ Na_2CO_3}$

$57.3 } *\frac {1 \ mol \ Na_2CO_3}{105.9875386 }$

$\frac {57.3 }{105.9875386 } \ mol \ Na_2CO_3$

$0.5406295944 \ mol \ Na_2CO_3$

The original measurement of moles has 3 significant figures, so our answer must have the same. For the number we found that is the thousandth place. The 6 in the ten-thousandth place to the right tells us to round the 0 up to a 1.

$0.541 \ mol \ Na_2CO_3$

There are approximately 0.541 moles of sodium carbonate in 57.3 grams.

6 0

2 years ago

400cm³ of dry air was passed over heated copper powder in a hard glass tube until no further change. What volume of remained at

Delicious77 [7]

Explanation:

I think there' will be a decrease in volume of the air.

3 0

2 years ago

Read 2 more answers

Which structure vibrates the hammer? stirrup ear canal eardrum anvil

sammy [17]

ANSWER: Eardrum

EXPLANATION:

The vibrations from the eardrum set the ossicles into motion. The ossicles are actually tiny bones — the smallest in the human body. The three bones are named after their shapes: the malleus (hammer), incus (anvil) and stapes (stirrup). The ossicles further amplify the sound.

5 0

2 years ago

Scientific Method

Leona [35]

Answer:

Problem, Variables, Hypothesis, Research, Procedure, Data, Conclusion.

Explanation:

First, you have to know what the problem that you're talking about is. Then, you have to know the independent, dependent, and controlled variables are in order to make a hypothesis. Then do research about the topic. After that, you make the procedure your experiment, if that's what your doing. Then after the experiment, you find the data. Using that data, you make a conclusion.

4 0

2 years ago