Answer
B. One element takes the place of another in a compound
Explanation
A single-replacement reaction occurs when one element is substituted for another element in a compound.The reacting materials are normally pure elements such as a metal or hydrogen gas with an aqueous compound.A new aqueous compound plus a different pure element are formed as products.
The melting of the ice cube indicates physical change has taken place
Explanation:
xác định nội năng chuẩn ΔU của phản ứng tổng hợp amoniac
ở 400 0 C, biết :
N 2(k) + 3H 2(k) = 2NH 3(k) ΔH 0 T = - 109,0 kJ
Answer:
Volume = 72.7272
Explanation:
if only pressure and volume change, then we can do some simple math to find the answer.
2 x 10 ^ 6 times 1 x 10 ^-5 = 20
pressure and volume must equal 20
20 = 0.275 x volume
20 / 0.275 = new volume
I don't remember significant digits but your volume is 72.72727272 just repeated
We use the osmotic pressure to determine the concentration of the solute in the solution. Then, we multiply the volume of the solution to determine the number of moles of solute particles. We need to establish to equations since we have two unknowns, the mass of of each solute. We do as follows:
osmotic pressure = CRT
<span>C = 7.75 / 0.08205 (296.15) = 0.3189 mol / L</span>
<span>moles of particles = C*V = 0.3189*0.250 =0.0797 mol </span>
<span>0.0797 = moles of sucrose + 2*moles of salt </span>
<span>x + 2y = 0.0797 </span>
<span>and </span>
<span>x(MMsucrose) + y(MMNaCl) = 10.2</span>
<span>342x + 58.5y = 10.2
</span>
<span>solve for x and y
</span>
<span>x = 0.0252 mol sucrose</span>
<span>y = 0.0273 mol NaCl
</span>
<span>mass Sucrose = 0.0252(342) = 8.6184 g </span>
<span>mass NaCl = 0.0273(58.5) = 1.5971 g </span>
<span>% NaCl = (1.5971 / 10.2)*100 = 15.66%</span>
