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Inessa05 [86]
2 years ago
13

Which keystone species feed on other animals and prevent them from damaging the ecosystem?.

Chemistry
1 answer:
DochEvi [55]2 years ago
7 0
Predators feed on other animals and keep the ecosystem in balance
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a european cheese making recipe calls for 2.50 kg of whole milk. An american wishes to make the recipe has only measuring cups,
Firlakuza [10]
To determine the number of cups of milk, we first calculate for the volume of the milk needed. Then, we use a conversion factor for the volume from cubic centimeter to cups. From literature, 1 cubic centimeter is equal to 0.0042 cup. We do as follows:

Volume of milk = ( 2.50 kg ) ( 1000 g / 1 kg ) / 1.03 g /cm^3 = 2427.18 cm^3
cups of milk = 2427.18 cm^3 ( 0.0042 cup / 1 cm^3 ) = 10.19 cups
5 0
3 years ago
How many electrons can be held in sub level I=3?
Zinaida [17]
2 is your answer hope you get it right
6 0
3 years ago
Write the empirical formula for at least four ionic compounds that could be formed from the following ions:
CaHeK987 [17]

Answer:

Fe(CN)₂,  FeCO₃,  Pb(CN)₄,  Pb(CO₃)₂

Explanation:

Cations (positively charged ions) can only form ionic bonds with anions (negatively charged ions). However, you can't just simply put one cation and one anion together to form a compound. Each compound needs to been neutral, or have an overall charge of 0. When cations and anions do not have charges that perfectly cancel, you need to modify the amount of each ion in the compound.

1.) Fe(CN)₂
-----> Fe²⁺ and CN⁻

-----> +2 + (-1) + (-1) = 0

2.) FeCO₃

-----> Fe²⁺ and CO₃²⁻

-----> +2 + (-2) = 0

3.)  Pb(CN)₄

-----> Pb⁴⁺ and CN⁻

-----> +4 + (-1) + (-1) + (-1) + (-1) = 0

4.) Pb(CO₃)₂

-----> Pb⁴⁺ and CO₃²⁻

-----> +4 +(-2) + (-2) = 0

5 0
2 years ago
12.<br> An object with a mass of 3 kg has a momentum of 75 kg•m/s. What is the velocity?
marissa [1.9K]

Answer:

the velocity is 25 m/s

Explanation:

The computation of the velocity is shown below:

As we know that

Magnitude of Momentum = (mass) × (speed)

75 kg. m/s = 3 kg × speed

So, the speed is

= 75 ÷ 3

= 25 m/s

hence, the velocity is 25 m/s

3 0
2 years ago
Use the given data at 500 K to calculate ΔG°for the reaction
Anton [14]

Answer : The  value of \Delta G^o for the reaction is -959.1 kJ

Explanation :

The given balanced chemical reaction is,

2H_2S(g)+3O_2(g)\rightarrow 2H_2O(g)+2SO_2(g)

First we have to calculate the enthalpy of reaction (\Delta H^o).

\Delta H^o=H_f_{product}-H_f_{reactant}

\Delta H^o=[n_{H_2O}\times \Delta H_f^0_{(H_2O)}+n_{SO_2}\times \Delta H_f^0_{(SO_2)}]-[n_{H_2S}\times \Delta H_f^0_{(H_2S)}+n_{O_2}\times \Delta H_f^0_{(O_2)}]

where,

\Delta H^o = enthalpy of reaction = ?

n = number of moles

\Delta H_f^0 = standard enthalpy of formation

Now put all the given values in this expression, we get:

\Delta H^o=[2mole\times (-242kJ/mol)+2mole\times (-296.8kJ/mol)}]-[2mole\times (-21kJ/mol)+3mole\times (0kJ/mol)]

\Delta H^o=-1035.6kJ=-1035600J

conversion used : (1 kJ = 1000 J)

Now we have to calculate the entropy of reaction (\Delta S^o).

\Delta S^o=S_f_{product}-S_f_{reactant}

\Delta S^o=[n_{H_2O}\times \Delta S_f^0_{(H_2O)}+n_{SO_2}\times \Delta S_f^0_{(SO_2)}]-[n_{H_2S}\times \Delta S_f^0_{(H_2S)}+n_{O_2}\times \Delta S_f^0_{(O_2)}]

where,

\Delta S^o = entropy of reaction = ?

n = number of moles

\Delta S_f^0 = standard entropy of formation

Now put all the given values in this expression, we get:

\Delta S^o=[2mole\times (189J/K.mol)+2mole\times (248J/K.mol)}]-[2mole\times (206J/K.mol)+3mole\times (205J/K.mol)]

\Delta S^o=-153J/K

Now we have to calculate the Gibbs free energy of reaction (\Delta G^o).

As we know that,

\Delta G^o=\Delta H^o-T\Delta S^o

At room temperature, the temperature is 500 K.

\Delta G^o=(-1035600J)-(500K\times -153J/K)

\Delta G^o=-959100J=-959.1kJ

Therefore, the value of \Delta G^o for the reaction is -959.1 kJ

3 0
3 years ago
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