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3 years ago

Which statement explains the method to adjust the strength of the flame on the Bunsen burner?

Chemistry

1 answer:

Anarel [89]3 years ago

4 0

Answer:

adjusting the air mix by rotating the barrel and adjusting the gas with the needle valve to obtain a flame of suitable height and intensity

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Round off each number to the indicated number significant figures (sf):

qaws [65]

Answer :

(a) The given number in 2 significant figures will be, $3.6\times 10^3$

(b) The given number in 4 significant figures will be, $3.583\times 10^1$

(c) The given number in 3 significant figures will be, $2.24\times 10^1$

Explanation :

Significant figures : The figures in a number which express the value -the magnitude of a quantity to a specific degree of accuracy is known as significant digits.

(a) The given number 00003554 converted into 2 significant figures.

In 00003554, there are 4 significant figures. Now we have to convert it into 2 significant figures.

The given number in 2 significant figures will be, $3.6\times 10^3$

(b) The given number 35.8348 converted into 4 significant figures.

In 35.8348, there are 6 significant figures. Now we have to convert it into 4 significant figures.

The given number in 4 significant figures will be, $3.583\times 10^1$

(c) The given number 22.4555 converted into 3 significant figures.

In 22.4555, there are 6 significant figures. Now we have to convert it into 3 significant figures.

The given number in 3 significant figures will be, $2.24\times 10^1$

7 0

3 years ago

N2 (g) + __ H2 (g) --> _NH3 When the reaction above is completely

Advocard [28]

Answer:

Explanation:

left side has 2 N so right side must have a 2 which means 6 H on right side so to get 6 on left you have a coef. of 3 to make 6 H

7 0

2 years ago

Use the balanced equation given below to solve the following problem; Calculate the volume in liters of CO produced by the react

Elan Coil [88]

Answer: 40.3 L

Explanation:

To calculate the moles :

$\text{Moles of solute}=\frac{\text{given mass}}{\text{Molar Mass}}$

$\text{Moles of} Sb_2O_3=\frac{175g}{291.5g/mol}=0.600moles$

$Sb_2O_3+3C\rightarrow 2Sb+3CO$

According to stoichiometry :

1 moles of $Sb_2O_3$ produces = 3 moles of $CO$

Thus 0.600 moles of $Sb_2O_3$ will produce= $\frac{3}{1}\times 0.600=1.80moles$ of $CO$

Volume of $CO=moles\times {\text {Molar volume}}=1.80moles\times 22.4L/mol=40.3L$

Thus 40.3 L of CO is produced.

6 0

2 years ago

What is the reaction type<br> 2 Mgl2+ Mn(SO3)2 → 2 MgSO3 + Mnl4

Oksana_A [137]

Answer:

The reaction type is double displacement

4 0

2 years ago

How can you determine which bond in a structure is more polar without using an electronegativity table?

UkoKoshka [18]

To know this you pretty much do have to kind of memorize a few electronegativities. I don't recall ever getting a table of electronegativities on an exam.
From the structure, you have:

I remember the following electronegativities most because they are fairly patterned:
EN
H
=
2.1
EN
C
=
2.5
EN
N
=
3.0
EN
O
=
3.5
EN
F
=
4.0
EN
Cl
=
3.5
Notice how carbon through fluorine go in increments of
~
0.5
. I believe Pauling made it that way when he determined electronegativities in the '30s.
Δ
EN
C
−
Cl
=
1.0
Δ
EN
C
−
H
=
0.4
Δ
EN
C
−
C
=
0.0
Δ
EN
C
−
O
=
1.0
Δ
EN
O
−
H
=
1.4
So naturally, with the greatest electronegativity difference of
4.0
−
2.5
=
1.5
, the
C
−
F
bond is most polar, i.e. that bond's electron distribution is the most drawn towards the more electronegative compound as compared to the rest.
When the electron distribution is polarized and drawn towards a more electronegative atom, the less electronegative atom has to move inwards because its nucleus was previously favorably attracted to the electrons from the other atom.
That means generally, the greater the electronegativity difference between two atoms is, the shorter you can expect the bond to be, insofar as the electronegative atom is the same size as another comparable electronegative atom.
However, examining actual data, we would see that on average, in conditions without other bond polarizations occuring:
r
C
−
Cl
≈
177 pm
r
C
−
C
≈
154 pm
r
C
−
O
≈
143 pm
r
C
−
F
≈
135 pm
r
C
−
H
≈
109 pm
r
O
−
H
≈
96 pm
So it is not necessarily the least electronegativity difference that gives the longest bond.
Therefore, you cannot simply consider electronegativity. Examining the radii of the atoms, you should notice that chlorine is the biggest atom in the compound.
r
Cl
≈
79 pm
r
C
≈
70 pm
r
H
≈
53 pm
r
O
≈
60 pm
So assuming the answer is truly
C
−
C
, what would have to hold true is that:
The
C
−
F
bond polarization makes the carbon more electropositive (which is true).
The now more electropositive carbon wishes to attract bonding pairs from chlorine closer, thereby shortening the
C
−
Cl
bond, and potentially the
C
−
H
bond (which is probably true).
The shortening of the
C
−
Cl
bond is somehow enough to be shorter than the
C
−
C
bond (this is debatable).

5 0

3 years ago

Read 2 more answers