Answer:
10.4g
Explanation are in the Picture
Answer:
47.2 g
Explanation:
Let's consider the following double displacement reaction.
3 FeCl₂ + 2 Na₃PO₄ → Fe₃(PO₄)₂ + 6 NaCl
The molar mass of Fe₃(PO₄)₂ is 357.48 g/mol. The moles corresponding to 44.3 g are:
44.3 g × (1 mol / 357.48 g) = 0.124 mol
The molar ratio of Fe₃(PO₄)₂ to FeCl₂ is 1:3. The moles of FeCl₂ are:
3 × 0.124 mol = 0.372 mol
The molar mass of FeCl₂ is 126.75 g/mol. The mass of FeCl₂ is:
0.372 mol × (126.75 g/mol) = 47.2 g
Answer:
The answer is 130.953 g of hydrogen gas.
Explanation:
Hydrogen gas is formed by two atoms of hydrogen (H), so its molecular formula is H₂. We can calculate is molecular weight as the product of the molar mass of H (1.008 g/mol):
Molecular weight H₂= molar mass of H x 2= 1.008 g/mol x 2= 2.01568 g
Finally, we obtain the number of mol of H₂ there is in the produced gas mass (264 g) by using the molecular weight as follows:
mass= 264 g x 1 mol H₂/2.01568 g= 130.9731703 g
The final mass rounded to 3 significant digits is 130.973 g
DE = dH - PdV
<span>2 H2O(g) → 2 H2(g) + O2(g) </span>
<span>You can see that there are 2 moles of gas in the reactants and 3 moles of gas in the products. </span>
<span>1 moles of ideal gas occupies the same volume as 1 mole of any other ideal gas under the same conditions of temp and pressure. </span>
<span>Since it is done under constant temp and pressure that means the volume change will be equal to the volume of 1 mole of gas </span>
<span>2 moles reacts to form 3 moles </span>
<span>The gas equation is </span>
<span>PV = nRT </span>
<span>P = pressure </span>
<span>V = volume (unknown) </span>
<span>n = moles (1) </span>
<span>R = gas constant = 8.314 J K^-1 mol^-1 </span>
<span>- the gas constant is different for different units of temp and pressure (see wikki link) in this case temp and pressure are constant, and we want to put the result in an equation that has Joules in it, so we select 8.314 JK^-1mol^-1) </span>
<span>T = temp in Kelvin (kelvin = deg C + 273.15 </span>
<span>So T = 403.15 K </span>
<span>Now, you can see that PV is on one side of the equation, and we are looking to put PdV in our dE equation. So we can say </span>
<span>dE = dH -dnRT (because PV = nRT) </span>
<span>Also, since the gas constant is in the unit of Joules, we need to convert dH to Joules </span>
<span>dH = 483.6 kJ/mol = 483600 Joules/mol </span>
<span>dE = 483600 J/mol - (1.0 mol x 8.314 J mol^-1K-1 x 403.15 K) </span>
<span>dE = 483600 J/mol - 3351.77 J </span>
<span>dE = 480248.23 J/mol </span>
<span>dE = 480.2 kJ/mol </span>
You would think that the bag of nails would have more mass but their masses are identical. <span>If you were to put them both in a vacuum chamber and let them fall from a great height, they would fall the same speed. The vacuum chamber would suck all of the air out of the cotton balls, thus making it heavier and weigh the same as the bag of nails.
Hopefully this is helpful and makes sense.</span>
