All categories

2 years ago

Which two statements describe organ systems working together to bring

Chemistry

2 answers:

morpeh [17]2 years ago

8 0

Answer is b hope this helps

ruslelena [56]2 years ago

6 0

Answer: A and C are the right answer.

Explanation:

You might be interested in

Why ammonium is not a molecular ion

In-s [12.5K]

Answer:

See below

Explanation:

Ammonium $(NH_{4}^+)$ is not a molecular ion because it is just a poly-atomic ion. A molecular ion has a "negative or positive charge" as a whole but the positive charge on here is not on the whole. So, it is a poly-atomic ion and not molecular ion.

3 0

3 years ago

Free-energy change, ΔG∘, is related to cell potential, E∘, by the equationΔG∘=−nFE∘where n is the number of moles of electrons t

mart [117]

Answer:

a) $\Delta G=372490 J$

b) $\Delta G=-568614 J$

Explanation:

a) The reaction:

$Mg(s) +Fe^{2+}(aq) \longrightarrow Mg^{2+}(aq) + Fe(s)$

The free-energy expression:

$\Delta G=-n*F*E$

$E=E_{red}-E_{ox]$

The element wich is reduced is the Fe and the one that oxidates is the Mg:

$-0.44V=E_{red}-(-2.37V)=1.93V$

The electrons transfered (n) in this reaction are 2, so:

$\Delta G=-2mol*96500 C/mol * 1.93 V$

$\Delta G=-372490 J$

b) If you have values of enthalpy and enthropy you can calculate the free-energy by:

$\Delta G=\Delta H - T* \Delta S$

with T in Kelvin

$\Delta G=-675 kJ*\frac{1000J}{kJ} - 298K*-357 J/K$

$\Delta G=-568614 J$

7 0

2 years ago

Lead forms two compounds with oxygen. One contains 2.98g of lead and 0.461g of oxygen. The other contains 9.89g of lead and 0.76

aliina [53]

The given question is incomplete, the complete question is:

Lead forms two compounds with oxygen. One contains 2.98g of lead and 0.461g of oxygen. The other contains 9.89g of lead and 0.763g of oxygen. For a given mass of oxygen, what is the lowest whole-number mass ratio of lead in the two compounds that combines with a given mass of oxygen?

Answer:

The lowest whole-number mass ratio in the two compounds is 1:2.

Explanation:

There is a need to find the mole ratio between lead and oxygen atoms in order to find the whole-number mass ratio of lead in the two compounds. In the first compound, the given mass of lead is 2.98 grams, the molar mass of lead is 207.2 gram per mole.

The no. of moles can be determined by using the formula,

moles = mass/molecular mass

moles = 2.98 g/207.2 g/mol

= 0.0144 moles

The mass of oxygen in the compound I is 0.461 grams, the molecular mass of oxygen is 16 gram per mol.

moles = 0.461 g /16 g/mol

= 0.0288 moles

The ratio between the lead and oxygen in the compound I is 0.0144/0.0288 = 1:2

On the other hand, in the compound II, the mass of lead given is 9.89 grams, therefore, the moles of lead in compound II is,

moles = 9.89 g / 207.2 g/mol

= 0.0477 moles

The mass of oxygen given in compound II is 0.763 grams, the moles of oxygen present in the compound II is,

moles = 0.763 g / 16 g

= 0.0477 moles

The ratio between the lead and oxygen in the compound II is, 0.0477 moles lead /0.0477 moles oxygen = 1:1

Hence, of the two compounds, the lowest ratio is found in the compound I, that is, 1:2.

4 0

3 years ago

Using the scientific method, design an experiment to test whether snow in Delaware makes better snowman than in New Jersey. Be s

FrozenT [24]

Answer:

Bro do the experiment and find it out

5 0

2 years ago

??? Ipc helppp pllzz

Umnica [9.8K]

The correct answers are
-formation of a precipitate
-bubble formation
-color change
-temperature change
-odor formation

The only one that isn’t correct is change in state of matter. A change in a state of matter does not mean it’s a chemical change. For example, water boiling so it turns into gas is not a chemical change, and is a physical one. Also, water can freeze and turn into ice, which is also still a physical change. If something changes state of matter, it does not necessarily mean it’s a chemical change.

5 0

2 years ago