This is how to solve the problem:
First, we need to find the qcalorimeter.
The, you must use the equation:
<span>qcalorimeter = Csp + (delta)T </span>
<span>(delta)T = is the same as what you used for
</span><span>CSP = you calculated this earlier in lab. "average heat capacity of the calorimeter" </span>
<span>Hope this helps answer your question.</span>
To solve this problem, we need to set-up algebraic expression. First, use variables to represent the number of beads.
Let: x = number of Xavier's beads
y = number of Y<span>aozhou's beads
z = number of Zara's beads
</span>It is important to note that since we have three unknowns, we should also have three independent equations. <span>Based on the given statements, we have the following three equations:
(1) x + y = 438
(2) x + z = 204
(3) y = 3z
Substitute y in terms of z in equation (1). Then multiply equation (2) with -1.
x + 3z = 438
-(x + z = 204)
-------------------
2z = 234
z = 117
From equation (3),
y = 3(117) = 351
Using equation (1),
x = 438 - 351 = 87
Thus, Xavier had 87 beads.</span>
Answer:
0.164541341 g H2
Explanation:
1) Convert grams to moles by dividing by RMM of Magnesium (24.31g).
2g Mg * (1 mol Mg / 24.31 g Mg) = 0.082270671 mol of Mg
2) Use the balanced equation's ratio of 1 mol Mg: 1 mol H2.
0.082270671 mol of Mg = 0.082270671 mol of H2
3) Convert the mol of H2 back into grams by multiplying by H2's RMM (2 g).
0.082270671 mol of H2 * 2 g H2 = 0.164541341 g H2
* Answer can be rounded to your liking *
Answer:
pH = 9.03
Explanation:
The equilibrium of the NH₄Cl / NH₃ buffer in water is:
NH₃ + H₂O ⇄ NH₄⁺ + OH⁻
Initial moles of both NH₃ and NH₄⁺ are:
0.100L ₓ (0.20 mol / L) = <em>0.0200 moles </em>
The NH₃ reacts with HCl producing NH₄⁺, thus:
NH₃ + HCl → NH₄⁺ + Cl⁻
<em>That means, moles of HCl added to the solution are the same moles are consumed of NH₃ and produced of NH₄⁺</em>
Moles added of HCl were:
0.025L ₓ (0.20mol / L) = 0.0050 moles of HCl. Thus, final moles of NH₃ and NH₄⁺ are:
NH₃: 0.0200 moles - 0.0050 moles = 0.0150 moles
NH₄⁺: 0.0200 moles + 0.0050 moles = 0.0250 moles.
Using H-H equation for bases:
pOH = pKb + log [NH₄⁺] / [NH₃]
<em>Where pKb is -log Kb =</em><em> 4.745</em><em>.</em>
Replacing:
pOH = 4.745 + log 0.0250mol / 0.0150mol
pOH = 4.967
As pH = 14- pOH
<em>pH = 9.03</em>
<em />
Answer:
2.3 x 10-23 g.
Explanation:
The mass of a single atom is the mass number, 14, is the mass in grams of one mole of carbon.
One mole of Nitrogen atom is 6.022 x 1023 atoms (Avogadro's number). This can then used to convert a nitogen atom to grams by the ratio:
mass of 1 atom / 1 atom = mass of a mole of atoms / 6.022 x 10^23 atoms.
mass of 1 atom = mass of a mole of atoms / 6.022 x 1023
mass of 1 N atom = 14 / 6.022 x 10^23 N atoms
mass of 1 N atom = 2.325 x 10^-23 g
The mass of a single Nitrogen atom is 2.325 x 10-23 g.
