I believe the correct answer would be the standard heat of formation. The keyword in the statement would be synthesis and standard state. Synthesis would always mean formation of something and standard states would mean at a temperature of 25 C and 1 atm pressure.
Answer:
Buffer is the chemical substance that addition of acids and bases, maintaining constant environment,its called Buffer.
Explanation:
- Buffers are use in the system to maintain the value of pH, and the contain the pH value is not to change.
- Buffer maintain the body of pH for the optimal activity,and they are solution of pH constant.
- Buffer in used in the lab and that to maintain growth of the micro tissues and the culture media.
- Buffer are used in maintain necessary optimal reaction activity,determine the indicator of solution with pH.
- Buffer capacity is that concentration to the buffering agent, is the very small increase,buffer capacity to the pH is 32% , of the maximum value of pH.
- Buffers in a acid regions to the desired of that value to the particular buffer agent.
- Buffers can be made from that a mixture of the base and acid, buffer can be a wide range of the obtained.
- Buffers that the pH calculation and they required to performed in the critic acid that the overlap over the buffer range.
Answer:
- Part a) 0.0104 moles copper(II) nitrate.
i) 0.0418 mole Cu
ii) 0.0209 mol Ag NO₃
Explanation:
<u>1) Balanced chemical reaction (single replacement):</u>
In a single replacement reaction a more acitve metal (Cu) replaces a less active metal (Ag)
- Cu + 2 Ag NO₃ → Cu (NO₃)₂ + 2 Ag
<u>2) Mole ratio: </u>
- 1 mole Cu : 2 mole Ag NO₃ : 2 mole Ag
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<u>3) Moles of Ag</u>
- n = mass in grams / atomic mass
- atomic mass of Ag: 107.868 g/mol
- n = 2.25 g / 107.868 g/mol = 0.0209 mol Ag
<u>4) Moles of copper(II) nitrate:</u>
- Set the proportion using the mole ratio:
- 2 mole Ag / 1 mole Cu (NO₃)₂ = 0.0209 mole Ag / x
- Solve: x = 0.0209 / 2 mole Cu (NO₃)₂ = 0.0104 moles Cu(NO₃)₂
That is the answer of part a: 0.0104 moles copper(II) nitrate.
<u>5) Moles of each reactant</u>
i) Cu:
- Set a proportion using the theoretical mole ratio
1 mole Cu / 2 mole Ag = x / 0.0209 mol Ag
- Solve for x: x = 0.0209 / 2 mole Cu = 0.0418 mole Cu
ii) Ag NO₃
- Set a proportion using the teoretical mole ratio
2 mole Ag NO₃ / 2 mole Ag = x / 0.0209 mole Ag
- Solve for x: x = 0.0209 mol Ag NO₃
When the volume is 450 cm3 so the boat will displace 450 g.
so we have 450 g - 14.5g = 435.5 left
so to get how many pennies can be added to the boat before it sinks can be determined by:
divided the mass for the one penny:
no.of Penny = 435.5 / 2.5g
= 174.2
∴ the boat will float with 174 pennies and will start to sink with 175
