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valentinak56 [21]
3 years ago
13

. -9 + 6 - (-2) Answers?

Chemistry
2 answers:
Kaylis [27]3 years ago
5 0
The answer is -1. 2 subtraction signs next to each other for an addition sign
Bumek [7]3 years ago
3 0

Answer:

-9+6-(-2)

-9+6+2

-9+8

-1 is the answer

Explanation:

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11. Propane (C3Hg) is a fuel commonly used in gas grills.
Mrac [35]

Answer:

81.71%

Explanation:

One mole of propane contains 3 moles of carbon atoms and 8 moles of hydrogen atoms, as seen from the molecular formula of C_3H_8. In order to calculate the percent of carbon in propane by mass, we need to remember that %w/w (or percent mass) formula states that:

\omega=\frac{m_{component}}{m_{total}}\cdot100\%

That is, we need to divide the mass of the component of interest by the total mass of the compound and multiply by 100 to obtain the percentage.

For simplicity, let's take 1 mole of propane and find the mass of 1 mole (hence, we'll be finding the molar mass of propane). To do that, we add the 3 molar masses of carbon and 8 molar masses of hydrogen to obtain a total of:

M_{C_3H_8}=3M_C+8M_H=3\cdot12.011 \frac{g}{mol}+8\cdot1.00784\frac{g}{mol}=44.096 \frac{g}{mol}

Now that we have the molar mass of propane, we also need to find the total mass of carbon in 1 mole of propane. We know that we have a total of 3 moles of carbon which corresponds to:

M_C=3\cdot12.011 \frac{g}{mol}=36.033 \frac{g}{mol}

Dividing the mass of carbon present by the total mass of the compound will yield the mass percentage as defined by the formula we introduced:

\omega_C=\frac{36.033\frac{g}{mol}}{44.096 \frac{g}{mol}}\cdot 100\%=81.71\%

5 0
3 years ago
Using these metal ion/metal standard reduction potentials calculate cell potential for Cu2+(aq) + Cd(s) →Cd2+(aq)+ Cu(s) Cu2+(aq
Katena32 [7]

Solution :

Cd(s) ---------------------->  Cd^{+2} (aq) + 2e^-      ,     E_0  =   0.34 v

Cu^{+2}  (aq)  +   2e^-  ------------> Cu (s)             ,     E_0  =  -0.04 v

----------------------------------------------------------------------------------------------

Cd(s)  +  Cu^{+2}  (aq)  ------------->  Cd^{+2} (aq)  +  Cu (s)   ,      E_0  =  0.30 v  

The cell potential is defined as the measure of \text{ potential difference }  between the \text{two half cells} of an electrochemical cell.  

4 0
3 years ago
Compare melting point freezing point and boiling point
Tresset [83]
Melting point- the temperature at which a substance has changed from a solid to a liquid
freezing- the temperature at which a substance chanes from liquid to a solid
boiling point- the temperature at which a substance changes from a liquid to a gas phase
4 0
3 years ago
How many grams of silver are in 4.2 moles of silver?
Phantasy [73]

Answer:

Solution: Since the atomic mass of silver (Ag) is 107.87 amu, one mole of silver has a mass o f 107.87 grams. Therefore, there is one mole of Ag per 107.87 grams of Ag

Explanation:

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3 years ago
Answer the lab question (“what is the effect of temperature on the solubility of a solid in a liquid?”) with a hypothesis:
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4 years ago
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