Answer:
a
Explanation:
first one i did the test trust me
Answer:
d. 
Explanation:
Mass of calcium = 4.00 g
Molar mass of calcium = 40.078 g/mol
<u>Moles of calcium = 4.00 / 40.078 moles = 0.9981 moles</u>
Given that the compound only contains calcium and bromine. So,
Mass of bromine in the sample = Total mass - Mass of calcium
Mass of the sample = 20.0 g
<u>Mass of bromine in sample = 20.0 - 4.00 g = 16.0 g</u>
Molar mass of bromine = 79.904 g/mol
<u>Moles of Bromine = 16.0 / 79.904 = 0.2002 moles
</u>
Taking the simplest ratio for Ca and Br as:
0.9981 : 0.2002 = 5 : 1
The empirical formula is =
<span>Hydrogen atoms accompany electrons as they are transferred in biological systems in order to ensure that the metabolism proceeds to completion.
This is considered the main purpose of the electron shuttles.
</span>
The answer is False Manys why
Answer:
-56.1kJ/mol
Explanation:
The reaction between HCl and NaOH is:
NaOH + HCl → NaCl + H₂O + ΔH
<em>Where ΔH is heat change in the reaction.</em>
<em />
As the temperature of the solution increases, the heat is released and ΔH < 0
The heat released in the reaction is obtained using coffe-cup calorimeter equation:
Q = C×m×ΔT
<em>Where Q is heat</em>
<em>C is specific heat of the solution (4.184J/g°C)</em>
<em>m is mass of solution: Assuming density = 1g/mL, 100mL of solution = 100g</em>
<em>And ΔT is change in temperature (13.4°C)</em>
<em />
Replacing:
Q = C×m×ΔT
Q = -4.184J/g°C×100g×13.4
Q = -5606.6J
Now, in the reaction you have:
<em>Moles HCl:</em>
0.050L * (2.2mol/L) = 0.11 moles
<em>Moles NaOH:</em>
0.050L * (2.0mol/L) = 0.1 moles
That means the moles of reaction are 0.1 moles, and heat change in the chemical reaction is:
5606.6J / 0.1 mol = 56066J =
<h3>-56.1kJ/mol</h3>
<em />
