An acid can be defined as a proton donor.
Answer:
The elements in each group have the same number of electrons in the outer orbital. Those outer electrons are also called valence electrons. They are the electrons involved in chemical bonds with other elements. Every element in the first column (group one) has one electron in its outer shell.
Explanation:
Answer : The internal energy change is, -506.3 kJ/mol
Explanation :
Formula used :
or,
where,
= change in enthalpy = 
= change in internal energy = ?
= change in moles
Change in moles = Number of moles of product side - Number of moles of reactant side
According to the reaction:
Change in moles = 0 - 2 = -2 mole
That means, value of 
= 0
R = gas constant = 8.314 J/mol.K
T = temperature = 
Now put all the given values in the above formula, we get
Therefore, the internal energy change is -506.3 kJ/mol
When the substance is creating gases. Sometimes when it’s bubbling up
Answer:
Explanation
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One
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Ca(OH)2 + 2HNO3 -----> Ca(NO3)2 + H2O
Focus on the NO3. This is an odd problem and you usually do not focus on the complex ion. But this one works easiest if you do.
The problem now is going to be the oxygens. There are 2 with the Calcium and only 1 free one going to the water. (The NO3 has been taken care of in the last step).
Ca(OH)2 + 2HNO3 -----> Ca(NO3)2 + 2H2O
Count the atoms. I think this equation is balanced.
atom Left Right Result
Ca 1 1 Balanced
O 8 8 Balanced
H 2 + 2 2*2 Balanced
N 2 2 Balanced
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Two
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CH4 + O2====> CO2 + H2O
Start with the hydrogens.
The right side requires a 2
CH4 + O2 ===> CO2 + 2H2O
Now look at the oxygens. There are 4 on the right. and only 2 on the left. You need to multiply O2 by 2
CH4 + 2O2 ===> CO2 + 2H2O
Each side has 1 Carbon 4 hydrogens and 4 oxygens. The equation is balanced.
