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kondaur [170]
3 years ago
8

An unknown substance has mass of 20 grams and volume of 2 cm3. What is the density of the substance

Chemistry
1 answer:
romanna [79]3 years ago
8 0
Density is the ratio of mass of as substance per unit volume of the same substance.
mass (20g)
volume (2cm3)
20g divide by 2cm3
therefore density is 10gcm-3
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I need help solving this!
zmey [24]

Answer: Moles of hydrogen required are 4.57 moles to make 146.6 grams of methane, CH_{4}.

Explanation:

Given: Mass of methane = 146.6 g

As moles is the mass of a substance divided by its molar mass. So, moles of methane (molar mass = 16.04 g/mol) are calculated as follows.

Moles = \frac{mass}{molar mass}\\= \frac{146.6 g}{16.04 g/mol}\\= 9.14 mol

The given reaction equation is as follows.

C + 2H_{2} \rightarrow CH_{4}

This shows that 2 moles of hydrogen gives 1 mole of methane. Hence, moles of hydrogen required to form 9.14 moles of methane is as follows.

Moles of H_{2} = \frac{9.14}{2}\\= 4.57 mol

Thus, we can conclude that moles of hydrogen required are 4.57 moles to make 146.6 grams of methane, CH_{4}.

5 0
3 years ago
What is the wave speed if the wave length is 8 and the frequency is 20
PilotLPTM [1.2K]

Answer:

160m/s

Explanation:

To find V Use the following formula V= F*W

V= Velocity F= Frequency W= Wavelength

V=20*8

=160m/s

4 0
3 years ago
Why dilute H2SO4 is added to oxali acid solution in redox reaction​
Sphinxa [80]

To prevent the hydrolysis and to catalyse the reaction.

Explanation:

  • Sulphuric acid is the catalyst and also a dehydrating agent in this reaction.
  • Sulphuric acid is using in redox reaction because sulphuric acid is providing H+ ions which is necessary for this reaction to occur more quickly, but the sulphate ions from the sulphuric acid barely react during this process. So H2SO4 is adding in this reaction to make it more acidic.
  • H2SO4 is preventing hydrolysis by providing excess H+ ions into the reaction. H2SO4 is stable towards the direction of oxidation.
7 0
3 years ago
a student prepares a dilute solution of sodium hydroxidem, NaOH (aq), starting with 6 M sodium hydroxide. She then titrates a 1.
Serjik [45]

Answer:

M = 0.3077 M

Explanation:

As I said in the comments, you are missing the required volume of the base to react with the KHP. I found this on another site, and the volume it used was 21.84 mL.

Now, KHP is a compound often used to standarize NaOH or KOH solutions. This is because it contains a mole ratio of 1:1 with the base, so it's pretty easy to use and standarize any base.

Now, as we are using an acid base titration, the general expression to use when a acid base titration reach the equivalence point would be:

n₁ = n₂   (1)

This, of course, if the mole ratio is 1:1. In the case of KHP and NaOH it is.

Now, we also know that moles can be expressed like this:

n = M * V   (2)

And according to this, we are given the volume of base and the required mass of KHP. So, if we want to know the concentration of the base, we need to get the moles of the KHP, because in the equivalence point, these moles are the same moles of base.

The reported molar mass of KHP is 204.22 g/mol, so the moles are:

n = 1.372 / 204.22 = 6.72x10⁻³ moles

Now, we will use expression (2) to get the concentration of the diluted base:

n = M * V

M = n / V

M = 6.72x10⁻³ / 0.02184

M NaOH = 0.3077 M

This is the concentration of the dilute solution of NaOH

3 0
3 years ago
Who is boo johnson ??
matrenka [14]

a skate border? i think ?



7 0
3 years ago
Read 2 more answers
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