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3 years ago

Calculate the number of kilojoules to warm 125 grams of iron from 23.5 degrees Celcius to 78 degrees Celcius

1 answer:

3 0

Q=mcΔT

q=(125g)(0.446 J/(g x °C))(78°C - 23.5°C)

q=(125 g)(0.446 J/(g x °C))(54.5°C) (Be sure to cancel all similar units)

q= 3038.375 J

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New questionWhat mass of calcium chloride (CaCl₂) would beproduced from the reaction of 125.9 g of hydrochloriacid (HCI) with ex

marshall27 [118]

Answer:

191.6 g of CaCl₂.

Explanation:

What is given?

Mass of HCl = 125.9 g.

Molar mass of CaCl₂ = 110.8 g/mol.

Molar mass of HCl = 36.4 g/mol.

Step-by-step solution:

First, we have to state the chemical equation. Ca(OH)₂ react with HCl to produce CaCl₂:

$Ca(OH)_2+2HCl\rightarrow CaCl_2+2H_2O.$

Now, let's convert 125.9 g of HCl to moles using the given molar mass (remember that the molar mass of a compound can be found using the periodic table). The conversion will look like this:

$125.9\text{ g HCl}\cdot\frac{1\text{ mol HCl}}{36.4\text{ g HCl}}=3.459\text{ moles HCl.}$

Let's find how many moles of CaCl₂ are being produced by 3.459 moles of HCl. You can see in the chemical equation that 2 moles of HCl reacted with excess Ca(OH)₂ produces 1 mol of CaCl₂, so we state a rule of three and the calculation is:

$3.459\text{ moles HCl}\cdot\frac{1\text{ mol CaCl}_2}{2\text{ moles HCl}}=1.729\text{ moles CaCl}_2.$

The final step is to find the mass of CaCl₂ using the molar mass of CaCl₂. This conversion will look like this:

$1.729\text{ moles CaCl}_2\cdot\frac{110.8\text{ g CaCl}_2}{1\text{ mol CaCl}_2}=191.6\text{ g CaCl}_2.$

The answer would be that we're producing a mass of 191.6 g of CaCl₂.

4 0

1 year ago

The standard free energy change for a reaction in an electrolytic cell is always:_________

sattari [20]

Answer: The standard free energy change for a reaction in an electrolytic cell is always positive.

Explanation:

Electrolytic cells use electric currents to drive a non-spontaneous reaction forward.

Relation of standard free energy change and emf of cell

$\Delta G^o=-nFE^0_{cell}$

where,

$\Delta G^o$ = standard free energy change

n= no of electrons gained or lost

F= faraday's constant

$E^0_{cell}$ = standard emf

$E^0_{cell}$ = standard emf = -ve , for non spontaneous reaction

Thus $\Delta G^o=(-ve)(-ve)=+ve$

Thus standard free energy change for a reaction in an electrolytic cell is always positive.

8 0

3 years ago

How do I find the moles of OH- which reacted (mol) in the titration. Table Attached

BaLLatris [955]

Answer:

It is equal to the number of moles of acid that reacted. When Oxalic acid is your limiting reactant it is the # of moles of oxalic acid used. When NaOH is your limiting reactant it is equal to the number of moles of NaOH used.

4 0

3 years ago

How many Oxygen atoms in: 5H2SO3

astra-53 [7]

Answer:

Explanation: I think

5 0

3 years ago

Read 2 more answers

How does the periodic table help I’m predicting the formula of a stable ionic compound

WITCHER [35]

The answer is B on edge

4 0

3 years ago