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3 years ago

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What happens to a redox reaction when it is shown as half-reactions answers?

1 answer:

ella [17]3 years ago

8 0

A redox reaction is a combination of an oxidation reaction and a reduction reaction, this reaction involves the transfer of electrons from one species to another. When redox reactions are shown as half reactions you are able to determine what parts of the reaction are being reduced and what is being oxidized. Moreover, you are able to determine if the reaction is spontaneous or not once you see the half reactions. When an element loses an electron in a reaction it is considered to be oxidized however if it gains an electron or multiple electrons then it is reduced. In other words, if the oxidation number increases then it is losing electrons and therefore it is oxidized but if the number is decreasing then it is gaining electrons. Note that electrons have negative charges so this trend only makes sense because of this fact.

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What elegant has 2 valence electrons

scZoUnD [109]

Explanation:

Calcium is the element that has 2 valence electrons.

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3 years ago

Name the two products when calcium carbonate (CaCO3) is heated

trapecia [35]

Answer:

The products are Calcium oxide and Carbon dioxide.

Explanation:

When calcium carbonate is heated, thermal decomposition occurs.

Calcium calcium → Calcium oxide + Carbon dioxide

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2 years ago

Read 2 more answers

A steel container with a movable piston contains 2.00 g of helium which was held at a constant temperature of 25 °C. Additional

shtirl [24]

Answer: D) 1.00 g

Explanation:

According to the Avogadro's law, the volume of gas is directly proportional to the number of moles of gas at same pressure and temperature. That means,

$V\propto n$

or,

$\frac{V_1}{V_2}=\frac{n_1}{n_2}$

where,

$V_1$ = initial volume of gas = 2.00 L

$V_2$ = final volume of gas = 3.00 L

$n_1$ = initial moles of gas = $\frac{\text {Given mass of helium}}{\text {molar mass of helium}}=\frac{2.00g}{4g/mol}=0.500mol$

$n_2$ = final moles of gas = ?

Now we put all the given values in this formula, we get

$\frac{2.00L}{3.00L}=\frac{0.500mol}{n_2}$

$n_2=0.75mole$

Mass of helium = $moles\times {\text {molar mass}}=0.75\times 4=3.00g$

Thus mass of helium added = (3.00-2.00) g = 1.00 g

4 0

3 years ago

In a certain city, electricity costs $0.15 per kW·h. What is the annual cost for electricity to power a lamp-post for 6.00 hours

Vanyuwa [196]

(a) Power of bulb is 100 W, converting this into kW.

$1 W=\frac{1}{1000}kW$

Thus,

$100 W =\frac{100}{1000}kW=0.1 kW$

The bulb is used for 6 hours per day for a year, in 1 year there are 365 days thus, total hours will be:

$t=6\times 365=2190 h$

Electricity used will depend on power and number of hours as follows:

$E=P\times t=0.1 kW\times 2190 h=219 kW.h$

The cost of electricity is $0.15 per kW.h thus, cost of electricity for 219 kW.h will be:

$Cost=\$ (219\times 0.15)=\$ 32.85$

Therefore, annual cost of incandescent light bulb is $\$ 32.85$

(b) Power of bulb is 25 W, converting this into kW.

$1 W=\frac{1}{1000}kW$

Thus,

$100 W =\frac{25}{1000}kW=0.025 kW$

The bulb is used for 6 hours per day for a year, in 1 year there are 365 days thus, total hours will be:

$t=6\times 365=2190 h$

Electricity used will depend on power and number of hours as follows:

$E=P\times t=0.025 kW\times 2190 h=54.75 kW.h$

The cost of electricity is $0.15 per kW.h thus, cost of electricity for 54.75 kW.h will be:

$Cost=\$ (54.75\times 0.15)=\$ 8.21$

Therefore, annual cost of fluorescent bulb is $\$ 8.21$ .

7 0

3 years ago

A sample of gas at 1.10 atm has a volume of 326 mL. What is the new volume if the pressure is changed to 1.90 atm?

Brut [27]

Answer

For this we use ideal gas equation which is:

P1V1 = P2V2

P1 = 1.10 atm

V1 = 326 ml

P2 = 1.90

V2 = ?

By rearranging the ideal gas equation:

V2 = P1V1 ÷ P2

V2 = 1.10 × 326 ÷1.90

V2 = 358.6 ÷ 1.90

V2 = 188.7 ml

8 0

3 years ago