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Vikki [24]
2 years ago
9

Is the dissolution of borax endothermic or exothermic.

Chemistry
1 answer:
Olin [163]2 years ago
8 0

Answer: Endothermic.

Explanation: ...

You might be interested in
Fe2O3 + CO --> Fe + CO2
satela [25.4K]

Answer:

The answer to your question is

1.-Fe₂O₃

2.- 280 g

3.- 330 g

Explanation:

Data

mass of CO = 224 g

mass of Fe₂O₃ = 400 g

mass of Fe = ?

mass of CO₂

Balanced chemical reaction

                       Fe₂O₃   + 3CO    ⇒  2Fe  +   3CO₂

1.- Calculate the molar mass of Fe₂O₃ and CO

Fe₂O₃ = (56 x 2) + (16 x 3) = 160 g

CO = 12 + 16 = 28 g

2.- Calculate the proportions

theoretical proportion Fe₂O₃ /3CO = 160/84 = 1.90

experimental proportion Fe₂O₃ / CO = 400/224 = 1.78

As the experimental proportion is lower than the theoretical, we conclude that the Fe₂O₃ is the limiting reactant.

3.-     160 g of Fe₂O₃  --------------- 2(56) g of Fe

         400 g of Fe₂O₃ ---------------  x

         x = (400 x 112) / 160

        x = 280 g of Fe

4.-      160 g of Fe₂O₃  --------------- 3(44) g of CO₂

          400 g of Fe₂O₃  --------------  x

          x = (400 x 132)/160

         x = 330 gr

3 0
3 years ago
How can a redox reaction be identified?
agasfer [191]

Answer:

'Oxidation states have changed.'

Explanation:

Redox Reactions can be identifiable by a change in oxidation number/states of two of the atoms in the reaction. Any reaction in which no oxidation numbers/state change is not a redox reaction.

3 0
2 years ago
A 0.25-mol sample of a weak acid with an unknown Pka was combined with 10.0-mL of 3.00 M KOH, and the resulting solution was dil
Masteriza [31]

Answer : The value of pK_a of the weak acid is, 4.72

Explanation :

First we have to calculate the moles of KOH.

\text{Moles of }KOH=\text{Concentration of }KOH\times \text{Volume of solution}

\text{Moles of }KOH=3.00M\times 10.0mL=30mmol=0.03mol

Now we have to calculate the value of pK_a of the weak acid.

The equilibrium chemical reaction is:

                          HA+KOH\rightleftharpoons HK+H_2O

Initial moles     0.25     0.03        0

At eqm.    (0.25-0.03)   0.03      0.03

                     = 0.22

Using Henderson Hesselbach equation :

pH=pK_a+\log \frac{[Salt]}{[Acid]}

pH=pK_a+\log \frac{[HK]}{[HA]}

Now put all the given values in this expression, we get:

3.85=pK_a+\log (\frac{0.03}{0.22})

pK_a=4.72

Therefore, the value of pK_a of the weak acid is, 4.72

7 0
3 years ago
During exercise your body's blood pressure increases as it cool down the body's blood pressure slowly returns to its normal stat
melamori03 [73]
Ur lungs i hope u get it
3 0
3 years ago
A student has 100. mL of 0.400 M CuSO4 (aq) and is asked to make 100. mL of 0.150 M CuSO4 (aq) for a spectrophotometry experimen
GenaCL600 [577]

Answer:

We have to take 37.5 mL of a 0.400 M solution

Explanation:

Step 1: Data given

Stock volume = 100 mL  = 0.100L

Stock concentration 0.400 M

Volume of solution he wants to make = 100 mL = 0.100L

Concentration of solution he wants to make = 0.150 M

Step 2: Calculate the volume of 0.400 M CuSO4 needed

C1*V1 = C2*V2

⇒with C1 = the stock concentration = 0.400M

⇒with V1 = the volume of the stock = TO BE DETERMINED

⇒with C2 = the concentration of the solution he wants to make = 0.150 M

⇒with V2 = the volume of the solution made = 0.100 L

0.400 M * V1 = 0.150M * 0.100L

V1 = (0.150M*0.100L) / 0.400 M

V1 = 0.0375 L = 37.5 mL

We have to take 37.5 mL of a 0.400 M solution

5 0
3 years ago
Read 2 more answers
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