Answer:
I would say A. I'm no expert, but it can't be C obviously, and I think wind would hit all of it, wearing off the top as well like the great pyramids. B would be my next choice, but A i think would be best.
Percent error is the difference between the measured and known value, divided by the known value, multiplied by 100%.
So first, we take our measured value, .299 cm, minus our known value, .225 cm.
.299 cm - .225 cm=.004 cm
Next, we divide that by our known value

Finally, multiply your answer by 100
.0177777778 x 100= 1.77777778 %
Round to three significant figures, and you're done.
=1.78 % error
Answer:
0,07448M of phosphate buffer
Explanation:
sodium monohydrogenphosphate (Na₂HP) and sodium dihydrogenphosphate (NaH₂P) react with HCl thus:
Na₂HP + HCl ⇄ NaH₂P + NaCl <em>(1)</em>
NaH₂P + HCl ⇄ H₃P + NaCl <em>(2)</em>
The first endpoint is due the reaction (1), When all phosphate buffer is as NaH₂P form, begins the second reaction. That means that the second endpoint is due the total concentration of phosphate that is obtained thus:
0,01862L of HCl×
= 1,862x10⁻³moles of HCl ≡ moles of phosphate buffer.
The concentration is:
= <em>0,07448M of phosphate buffer</em>
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I hope it helps!
The reaction will produce solid copper and aluminium chloride salt.
Explanation:
Copper chloride (CuCl₂) in solution will react with aluminium to form solid cooper and aluminium chloride (AlCl₃).
3 CuCl₂ (aq) + 2 Al (s) → 3 Cu (s) + 2 AlCl₃ (aq)
Learn more about:
numerical problems with copper chloride and aluminium
brainly.com/question/8827783
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Answer:
1.26 M
Explanation:
The ion nitrate is NO₃⁻ and the Barium is from group 2 so it forms the ion Ba²⁺, so the barium nitrate has the formula: Ba(NO₃)₂. The molar masses are: Ba: 137 g/mol, N = 14 g/mol, O = 16 g/mol, so the molar mass of barium nitrate is:
137 + 2x(14 + 3x16) = 199 g/mol
The number of moles is the mass divided by the molar mass, so:
n = 25.1/199 = 0.126 mol of Ba(NO₃)₂
In 1 mol of the salt, there are 2 moles of NO₃⁻, so the number of moles of nitrate is 0.252 mol. Nitrates formed with ammonium (that can react when the solid dissolves) and with elements from group 1 and 2 are completely soluble in water. So, the moles of nitrate will remain 0.252 mol.
The molarity is the number of moles divided by the volume (0.2 L):
[NO₃⁻]= 0.252/0.2 = 1.26 M