Answer:
3. Tails of phospholipids are hydrophobic.
Explanation:
According to the fluid mosaic model, the plasma or cell membrane contains components such as: proteins, phospholipids etc. The phospholipid forms a layer called PHOSPHOLIPID LAYER, which comprises of a phosphate head and a fatty acid (lipid) tail.
The phosphate head is HYDROPHILIC i.e. water-logging while the fatty acid/lipid tail is HYDROPHOBIC i.e. water-fearing. Hence, according to this question, it is TRUE that the tails of phospholipids are hydrophobic.
Note: Phospholipid layer, which are selectively-permeable i.e do not allow the passage of molecules, allows the passage/diffusion of small molecules like oxygen gas.
I think the best answer from the choices listed above is option B. The best graduated cylinder for this case is the glass cylinder. A metal cylinder is not possible because you cannot measure really since metals are not transparent. A plastic cylinder cannot also be used since the substance should be heated for the experiment.
Momentum is a term used to quantify the motion of an object has. It is calculated as the the product of the object's mass and the velocity. It is expressed as:
Momentum = m x vMomentum = 50 kg x 5 m/sMomentum = 250 kg m/s
Therefore, the correct answer is the last option.
Answer:
Explanation:
2. You work for an environmental company as an environmental toxicologist and have been hired to determine the contaminant present in a local resident’s pool. Create a flow chart outlining how you would detect the possible presence of Fe2+ and/or Sr2+
Answer:
a) 90 kg
b) 68.4 kg
c) 0 kg/L
Explanation:
Mass balance:

w is the mass flow
m is the mass of salt

v is the volume flow
C is the concentration





![-[ln(2000L+3*L/min*t)-ln(2000L)]=ln(m)-ln(90kg)](https://tex.z-dn.net/?f=-%5Bln%282000L%2B3%2AL%2Fmin%2At%29-ln%282000L%29%5D%3Dln%28m%29-ln%2890kg%29)
![-ln[(2000L+3*L/min*t)/2000L]=ln(m/90kg)](https://tex.z-dn.net/?f=-ln%5B%282000L%2B3%2AL%2Fmin%2At%29%2F2000L%5D%3Dln%28m%2F90kg%29)
![m=90kg*[2000L/(2000L+3*L/min*t)]](https://tex.z-dn.net/?f=m%3D90kg%2A%5B2000L%2F%282000L%2B3%2AL%2Fmin%2At%29%5D)
a) Initially: t=0
![m=90kg*[2000L/(2000L+3*L/min*0)]=90kg](https://tex.z-dn.net/?f=m%3D90kg%2A%5B2000L%2F%282000L%2B3%2AL%2Fmin%2A0%29%5D%3D90kg)
b) t=210 min (3.5 hr)
![m=90kg*[2000L/(2000L+3*L/min*210min)]=68.4kg](https://tex.z-dn.net/?f=m%3D90kg%2A%5B2000L%2F%282000L%2B3%2AL%2Fmin%2A210min%29%5D%3D68.4kg)
c) If time trends to infinity the division trends to 0 and, therefore, m trends to 0. So, the concentration at infinit time is 0 kg/L.