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strojnjashka [21]
3 years ago
15

Which of the following elements has three valence electrons? (2 points)

Chemistry
1 answer:
il63 [147K]3 years ago
7 0

Answer:

Al

Explanation:

It has 3.

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Consider the reaction 2 CO + O2 → 2 CO2 .What is the percent yield of carbon dioxide
Wewaii [24]

Answer:

Y=50.9\%

Explanation:

Hello,

In this case, given the reaction, we can directly compute the theoretically yielded grams of carbon dioxide, considering the 2:2 molar ratio between carbon monoxide (molar mass = 28 g/mol) and carbon dioxide (molar mass = 44 g/mol) and the initial reacting grams of carbon monoxide in excess oxygen:

m_{CO_2}^{theoretical}=10gCO*\frac{1molCO}{28gCO}*\frac{2molCO_2}{2molCO}*\frac{44gCO_2}{1molCO_2}   =15.7gCO_2

Thus, as only 8 g were actually yielded, we compute the percent yield:

Y=\frac{8g}{15.7g}*100\% \\\\Y=50.9\%

Best regards.

7 0
3 years ago
An electrochemical cell is powered by the half reactions shown below.
andrezito [222]
Reduction reactions are those reactions that reduce the oxidation number of a substance. Hence, the product side of the reaction must contain excess electrons. The opposite is true for oxidation reactions. When you want to determine the potential difference expressed in volts between the cathode and anode, the equation would be: E,reduction - E,oxidation. 

To cancel out the electrons, the e- in the reactions must be in opposite sides. To do this, you reverse the equation with the negative E0, then replacing it with the opposite sign. 

Pb(s) --> Pb2+ +2e-      E0 = +0.13 V
Ag+ + e-  ---> Ag           E0 = +0.80 V

Adding up the E0's would yield an overall electric cell potential of +0.93 V.
7 0
4 years ago
When calculating the equilibrium constant, what do the exponents represent?
guapka [62]

Answer:

The exponents mean add the numbers or time the number.

Explanation:

5 0
3 years ago
PLSSS HELP IF YOU KNOW THISS
mixas84 [53]

Answer:

C

Explanation:

Introspection is the examination of one's own conscious thoughts and feelings.

Introspection is closely related to human self-reflection and self-discovery and is contrasted with external observation.

8 0
3 years ago
Read 2 more answers
Chemical equation for heat of formation of c25h52
Alexus [3.1K]
 its exothermic. exothermic means the reaction gives out heat. [exo meaning outside and thermic meaning heat] because its a combustion reaction, fire is there meaning lots of heat. 
endothermic means it takes in heat. a good example is ammonium and water (NH3 +H20) 
<span>most chemical reaction are exothermic</span>
8 0
4 years ago
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