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2 years ago

A biological community together with its physical habitat constitutes a(n) ____________ .

Chemistry

1 answer:

lesya [120]2 years ago

4 0

Answer:

Ecosystem

Explanation:

I got the answer from the Mcgrawhill textbooks.

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Plz answer ASAP!

Alchen [17]

What types of atoms typically form covalent bonds?

The correct answer:

d) Nonmetals with nonmetals, because their difference in electronegativity is below 1.7.

En example to explain:
An example of a covalent bonding: HCl -> 2 nonmentals
-> a difference in electronegativity less than 1.7:

EN(Cl) = 3.0 and EN (H) = 2.1 (you can search these values in a periodic table)
/\EN = 3.0 - 2.1 = 0.9

0.9 < 1.7

I hope this helped you out!

4 0

2 years ago

Read 2 more answers

Which of these elements have the same number of valance electrons

solmaris [256]

Both carbon and lead belong to Group IV elements, and thus they have the same number of valence electrons.
In each of the other options, the two elements belong to different groups, and thus they do NOT have the same number of valence electrons.

I hope this helped you, please tell me if I am correct or not <3

6 0

2 years ago

Natalia dipped two feathers in oil. Then she dipped one feather in cold water and the other feather in hot water. She swirled bo

Alika [10]

Answer:

The hot water was better for removing the oil.

Explanation:

You can see that because the mass went down more with the hot water. So, that means that more oil was taken out of the feather with hot water.

8 0

1 year ago

During lab, a student used a Mohr pipet to add the following solutions into a 25 mL volumetric flask. They calculated the final

kompoz [17]

Answer:

(FeSCN⁺²) = 0.11 mM

Explanation:

Fe ( NO3)3 (aq) [0.200M] + KSCN (aq) [ 0.002M] ⇒ FeSCN+2

M (Fe(NO₃)₃ = 0.200 M

V (Fe(NO₃)₃ = 10.63 mL

n (Fe(NO₃)₃ = 0.200*10.63 = 2.126 mmol

M (KSCN) = 0.00200 M

V (KSCN) = 1.42 mL

n (KSCN) = 0.00200 * 1.42 = 0.00284 mmol

Total volume = V (Fe(NO₃)₃ + V (KSCN)

= 10.63 + 1.42

= 12.05 mL

Limiting reactant = KSCN

So,

FeSCN⁺² = 0.00284 mmol

M (FeSCN⁺²) = 0.00284/12.05

= 0.000236 M

Excess reactant = (Fe(NO₃)₃

n(Fe(NO₃)₃ = 2.126 mmol - 0.00284 mmol

=2.123 mmol

For standard 2:

n (FeSCN⁺²) = 0.000236 * 4.63

=0.00109

V(standard 2) = 4.63 + 5.17

= 9.8 mL

M (FeSCN⁺²) = 0.00109/9.8

= 0.000111 M = 0.11 mM

Therefore, (FeSCN⁺²) = 0.11 mM

7 0

2 years ago

Determine the molality of a solution of methanol dissolved in ethanol for which the mole fraction of methanol is 0.135. Give you

Alja [10]

Answer: The molality of the solution is 0.11 m

Explanation:

We are given:

Mole fraction of methanol = 0.135

This means that 0.135 moles of methanol is present in 1 mole of a solution

Moles of ethanol = 1 - 0.135 = 0.865 moles

To calculate the mass for given number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$

Moles of ethanol = 0.865 moles

Molar mass of ethanol = 46 g/mol

$0.865mol=\frac{\text{Mass of ethanol}}{46g/mol}\\\\\text{Mass of ethanol}=(0.865mol\times 46g/mol}=39.79g$

To calculate the molality of solution, we use the equation:

$Molality=\frac{m_{solute}\times 1000}{M_{solute}\times W_{solvent}\text{ (in grams)}}$

Where,

$m_{solute}$ = Given mass of solute (methanol) = 0.135 g

$M_{solute}$ = Molar mass of solute (methanol) = 32 g/mol

$W_{solvent}$ = Mass of solvent (ethanol) = 39.79 g

Putting values in above equation, we get:

$\text{Molality of methanol}=\frac{0.135\times 1000}{32\times 39.79}\\\\\text{Molality of methanol}=0.106m\approx 0.11m$

Hence, the molality of the solution is 0.11 m

6 0

2 years ago