In letters a and b, the "?" is a "-".
Answer:
a. - 1.051 V
Explanation:
In a redox reaction, one substance will oxide (lose electrons) and the other will reduce (gain electrons). The potential of reduction can be calculated by placing a redox reaction with H₂, which has a potential equal to 0.
For a spontaneous reaction, the electrons go from the anode (oxidation) to the cathode (reduction), and then the potential of the cell is the cathode potential lesse the anode potential:
E°cell = E°c - E°a
1.587 = 0.536 - E°a
E°a = 0.536 - 1.587
E°a = -1.051 V
Answer:
Secondary consumers
Explanation:
Carnivores are organisms that only eat meat and that rely on others for food and energy; this means that they cannot produce food themselves.
Look at the answer choices:
- Decomposers: these are organisms that break down dead matter into material that can be used later by plants to grow; carnivores do not break down dead matter; rather, they eat meat.
- Primary consumers: these are usually herbivores; they are the second level of the energy pyramid, and they eat the organisms at the bottom level. The organisms at the bottom level are plants that make their own food. Obviously, plants are not meat, so carnivores are not primary consumers.
- Producers: these are the plants at the bottom of the energy pyramid that make their own food. Carnivores do not make their own food.
Thus, the answer is secondary consumers because this level of organisms eat the organisms at the primary consumer level.
Hope this helps!
<u>Given:</u>
Mass of calcium nitrate (Ca(NO3)2) = 96.1 g
<u>To determine:</u>
Theoretical yield of calcium phosphate, Ca3(PO4)2
<u>Explanation:</u>
Balanced Chemical reaction-
3Ca(NO3)2 + 2Na3PO4 → 6NaNO3 + Ca3(PO4)2
Based on the reaction stoichiometry:
3 moles of Ca(NO3)2 produces 1 mole of Ca3(PO4)2
Now,
Given mass of Ca(NO3)2 = 96.1 g
Molar mass of Ca(NO3)2 = 164 g/mol
# moles of ca(NO3)2 = 96.1/164 = 0.5859 moles
Therefore, # moles of Ca3(PO4)2 produced = 0.0589 * 1/3 = 0.0196 moles
Molar mass of Ca3(PO4)2 = 310 g/mol
Mass of Ca3(PO4)2 produced = 0.0196 * 310 = 6.076 g
Ans: Theoretical yield of Ca3(PO4)2 = 6.08 g
Answer:
Explanation:
We are asked to find the specific heat capacity of a sample of lead. The formula for calculating the specific heat capacity is:
The heat absorbed (Q) is 237 Joules. The mass of the lead sample (m) is 22.7 grams. The change in temperature (ΔT) is the difference between the final temperature and the initial temperature. The temperature increases <em>from</em> 29.8 °C <em>to </em>95.6 °C.
- ΔT = final temperature -inital temperature
- ΔT= 95.6 °C - 29.8 °C = 65.8 °C
Now we know all three variables and can substitute them into the formula.
- Q= 237 J
- m= 22.7 g
- ΔT = 65.8 °C
Solve the denominator.
- 22.7 g * 65.8 °C = 1493.66 g °C
Divide.
The original values of heat, temperature, and mass all have 3 significant figures, so our answer must have the same. For the number we found that is the thousandth place. The 6 in the ten-thousandth place tells us to round the 8 up to a 9.
The specific heat capacity of lead is approximately <u>0.159 Joules per gram degree Celsius.</u>
