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3 years ago

3. What is an element?

Chemistry

2 answers:

laila [671]3 years ago

7 0

Answer:

copper

Explanation:

it's on the periodic table of elements

katrin2010 [14]3 years ago

3 0

Copper i believe is the correct answer

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A solution has a oh- = 1 x 10-5 m what are the h30 and the ph of the solution

Deffense [45]

I think it's easiest to find the pOH from the given [OH-] first.

-log(1x10^-5)

pOH=5

Then find the pH.

pOH+pH=14

5+pH=14

pH=9

Then find the [H+] using the pH.

antilog(-9) (if you dont have an antilog button use 10^-9)

[H+]=1x10^-9

3 0

3 years ago

Read 2 more answers

A buffer can be prepared by mixing two solutions. Determine if each of the following mixtures will result in a buffer solution o

GenaCL600 [577]

Answer:

The answers are in the explanation

Explanation:

A buffer is the mixture of a weak acid with its conjugate base or vice versa. Thus:

1) Mixing 100.0 mL of 0.1 M HF with 100.0 mL of 0.05 M mol KF. Will result in a buffer because HF is a weak acid and KF is its conjugate base.

2) Mixing 100.0 mL of 0.1 M NH₃ with 100.0 mL of 0.1 M NH₄Br. Will not result in a buffer because NH₃ is a strong base.

3) Mixing 100.0 mL of 0.1 M HCN with 100.0 mL of 0.05 M KOH. Will result in a buffer because HCN is a weak acid and its reaction with KOH will produce CN⁻ that is its conjugate base.

4) Mixing 100.0 mL of 0.1 M HCl with 100.0 mL of 0.1 M KCl Will not result in a buffer because HCl is a strong acid.

5) Mixing 100.0 mL of 0.1 M HCN with 100.0 mL of 0.1 M KOH Will not result in a buffer because each HCN will react with KOH producing CN⁻, that means that you will have just CN⁻ (Conjugate base) without HCN (Weak acid).

I hope it helps!

6 0

3 years ago

Calcium oxide reacts with water in a combination reaction to produce calcium hydroxide. Ca) + H2O --> Ca(OH)2 In a particular

mars1129 [50]

Answer:

Percent yield = 92.5%

Explanation:

The question asks for the percent yield which can be defined as:

$\frac{actual yield}{theoretical yield} .100$

Where the actual yield is how much product was obtained, in this case 6.11 g of Ca(OH)₂, and the theoretical yield is how much product could be obtained with the given reactants theoretically, that is if the reaction would work perfectly. So we need to calculate first the theoretical yield.

1. First lets write the chemical equation reaction correctly and check that it is balanced:

CaO + H₂O → Ca(OH)₂

2. Calculate the amount of product Ca(OH)₂ that can be obtained with the given reactants (theoretical yield), which are 5.00g of CaO and excess of water. So the amount of CaO will determined how much Ca(OH)₂ we can obtained.

For this we'll use the molar ratio between CaO and Ca(OH)₂ which we see it is 1:1. For every mol of CaO we'll obtain a mol of Ca(OH)₂. So lets convert the 5.00 g of CaO to moles:

Molar Mass of CaO: 40.078 + 15.999 = 56.077 g/mol

moles of CaO = 5.00 g / 56.077 g/mol = 0.08916 moles

As we said before from the molar ratio moles of Ca(OH)₂ = moles of CaO

So the moles of Ca(OH)₂ that can be obtained are 56.077 g/mol

We need to convert this value to grams:

Molar Mass of Ca(OH)₂ = 40.078 + (15.999 + 1.008)*2 = 74.092 g/mol

Theoretical yield of Ca(OH)₂ = 0.08916 moles x 74.092 g/mol = 6.606 g

3. Calculate the percent yield:

$\frac{actual yield}{theoretical yield} .100$

Percent yield = (6.11 g / 6.606g) x 100 = 92.5 %

5 0

3 years ago

Read 2 more answers

Please help me with this question! question number 2 only! PLEASE!!!

jeka57 [31]

Answer:

I'm not completely sure but possibly (HCO³)

6 0

3 years ago

How to add moisture to the air without a humidifier?

Verdich [7]

There are quite a few ways to add moisture into the air without a humidifier

A few things that can help add moisture are hanging your clothing to dry. hang drying your damp clothes will add moisture to the air over time as it evaporates and it will make your house smell like fresh clothes.

Another thing is a bath, allow the water to cool off and leave the bathroom door open, the steam will add moisture to the air as the water cools.

This might seem silly but putting bowls or vases of water out on the windowsill on a sunny day mill moistens the air as it evaporates.

You can also get houseplants, moisture evaporates from the leaves and stems of plants. transpiration can help increase the humidity in your home.

not sure if this is the answer you were looking for but if so im glad i could help. have a great day!

6 0

2 years ago

3. What is an element?​

3. What is an element?