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3 years ago

Please help and thank you

Chemistry

2 answers:

Natasha2012 [34]3 years ago

8 0

Answer: Its c

Explanation: i did it

mestny [16]3 years ago

6 0

Answer:

c but not sure

Explanation:

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If the heat capacity of an object is known, what other information will need to be known to calculate its specific heat capacity

zimovet [89]

Answer:

B. its temperature

Explanation:

4 0

2 years ago

Read 2 more answers

Read the Safety Data Sheet of hydrogen peroxide to identify the recommended way to store this substance. Choose one:_______.

Lena [83]

Answer:

The correct option is C.

In a tightly closed container in a dry and well-ventilated place

Explanation:

Hydrogen peroxide should be store in a tight closed container and ventilated area because it is an oxidizing agent and it's has oxidizing characteristics. If to is exposed or the bottle lid is broken and exposed it can react and liberate oxygen and heat. It can react with the air and chemical it is exposed with. This will make it to be less effective and there will be a change in it's composition.

5 0

3 years ago

Vapor obtained by evaporating 0.495 grams of an unknown liquid is collected in a 127 mL flask. At 371 K, the pressure of the vap

lidiya [134]

Answer:

The molar mass in g/mol is 121.4 g/m

Explanation:

Let's apply the Ideal Gases Law to solve this:

P . V = n . R. T

V = 125 mL → 0.125L

P = 754 Torr

760 Torr ___ 1 atm

754 Torr ____ (754 / 760) = 0.992 atm

Moles = Mass / Molar mass

0.992 atm . 0.125L = (0.495 g / MM) . 0.082 . 371K

(0.992 atm . 0.125L) / (0.082 . 371K) = (0.495 g / MM)

4.07x10⁻³ mol = 0.495 g / MM

MM = 0.495 g / 4.07x10⁻³ mol → 121.4 g/m

3 0

3 years ago

If 25.3 grams of mercury(II) oxide react to form 23.4 grams of mercury, how many grams of oxygen must simultaneously be formed?

sergij07 [2.7K]

Answer : The mass of oxygen formed must be 3.8 grams.

Explanation :

Law of conservation of mass : It states that mass can neither be created nor be destroyed but it can only be transformed from one form to another form.

This also means that total mass on the reactant side must be equal to the total mass on the product side.

The balanced chemical reaction will be,

$2HgO\rightarrow 2Hg+O_2$

According to the law of conservation of mass,

Total mass of reactant side = Total mass of product side

Total mass of $2HgO$ = Total mass of $2Hg+O_2$

As we are given :

The mass of $HgO$ = 25.3 grams

The mass of $Hg$ = 23.4 grams

So,

$2\times 25.3g=2\times 23.4g+\text{Mass of }O_2$

$50.6g=46.8g+\text{Mass of }O_2$

$\text{Mass of }O_2=3.8g$

Therefore, the mass of oxygen formed must be 3.8 grams.

6 0

3 years ago

Calculate the number of milliliters of 0.440 M KOH required to precipitate all of the Fe2+ ions in 187 mL of 0.692 M FeSO4 solut

EleoNora [17]

Answer:

588.2 mL

Explanation:

FeSO₄(aq) + 2KOH(aq) → Fe(OH)₂(s) + K₂SO₄(aq)

First we calculate how many Fe⁺² moles reacted, using the given concentration and volume of FeSO₄ solution (the number of FeSO₄ moles is equal to the number of Fe⁺² moles):

moles = molarity * volume

187 mL * 0.692 M = 129.404 mmol Fe⁺²

Then we convert Fe⁺² moles to KOH moles, using the stoichiometric ratios:

129.404 mmol Fe⁺² * $\frac{2mmolKOH}{1mmolFeSO_4}$ = 258.808 mmol KOH

Finally we calculate the required volume of KOH solution, using the given concentration and the calculated moles:

volume = moles / molarity

258.808 mmol KOH / 0.440 M = 588.2 mL

6 0

3 years ago