1. what is galena chemical formula
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Answer:

30.0ml

Explanation:

Half of fifty is 25 and 25 represents 15.0ml so 15.0ml×2=30.0ml there for 25+25 is 50

Answer:

1-if u are answering light waves question , then the answer is translucent mirror or objects

2- Oxygen

3- compass

Answer: The percent yield of zinc carbonate is 5.91 %

Explanation:

To calculate the moles :

[tex]\text{Moles of solute}=\frac{\text{given mass}}{\text{Molar Mass}}[/tex]

 [tex]\text{Moles of} ZnCO_3=\frac{12.6 g}{125.4g/mol}=0.100moles[/tex]

[tex]ZnI_2[/tex] is the limiting reagent as it limits the formation of product and [tex]Na_2CO_3[/tex] is the excess reagent.  

[tex]Na_2CO_3+ZnI_2\rightarrow 2NaI+ZnCO_3[/tex]  

According to stoichiometry :

1 mole of produce =  1 mole of

Thus 1.7 moles of [tex]ZnI_2[/tex] will produce=[tex]\frac{1}{1}\times 1.7=1.7moles[/tex]  of [tex]ZnCO_3[/tex]

Theoretical yield of [tex]ZnCO_3=moles\times {\text {Molar mass}}=1.7moles\times 125.4g/mol=213.2g[/tex]

percentage yield = [tex]\frac{\text {Experimental yield}}{\text {Theoretical yield}}\times 100=\frac{12.6g}{213.2g}\times 100=5.91\%[/tex]

Answer:

the other person was right EXCEPT it says in 2 significant numbers so the answer is 5.9

Explanation:

i hope this helps. have a wonderful day :))

Answer:

3

H+ and OH-

Explanation:

Answer:

Add a proton and add a neutron

Answer:

1. Mass of KCl produced = 774.8 g of KCl

2. Mass of KNO₃ produced = 13.837g

3. Moles of NaOH made = 0.846 moles

4. Moles of LiCl produced = 0.846 moles

5. Moles of CO₂ produced = 207.6 moles

Explanation:

1. From the equation of reaction, 1 mole of ZnCl₂ produces, 2 moles of KCl.

5.02 moles of ZnCl₂ will produce, 2 × 5.02 moles of KCl = 10.4 moles of KCl

Molar mass of KCl = (39 + 35.5) g/mol = 74.5 g/mol

10.4 moles of KCl = 10.4 × 74.5 g

Mass of KCl produced = 774.8 g of KCl

2. Mole ratio of KNO₃ and KOH = 1:1

O.137 moles of KOH will produce 0.137 moles of KNO₃

Molar mass of KNO₃ = 101 g/mol

Mass of KNO₃ produced = 0.137 × 101 g = 13.837g

3. Molar mas of Ca(OH)₂ = 74.0 g

Moles of Ca(OH)₂ in 31.3 g = 31.3/74.0 = 0.423 moles of Ca(OH)₂

Mole ratio of NaOH and Ca(OH)₂ in the reaction = 2 : 1

Moles of NaOH made = 2 × 0.423 = 0.846 moles

4. Molar mass of MgCl₂ = 95.0 g

Moles of MgCl₂ in 40.2 g = 40.2/95.0 = 0.423 moles

From the reaction equation, mole ratio of MgCl₂ and LiCl = 1:2

Moles of LiCl produced = 2 × 0.423 = 0.846 moles

5. From the equation of reaction, 1 mole of C₆H₁₀O₅ produces 6 moles of cO₂

34.6 moles of C₆H₁₀O₅ will produce 34.6 × 6 moles of CO₂

Moles of CO₂ produced = 207.6 moles

Answer:

Thymus. This gland makes white blood cells called T-lymphocytes that fight infection and are crucial as a child's immune system develops

Answer:

The answer is B

Explanation:

I'm just big-brained

And because it's hotter than the rest and since all of them are cold "B" is just going to make them warmer.

Answer:

The conduction was made by the foil which was touching the chocolate made the chocolate slowly melt because of the tea light giving heat to the foil the foil conducted it to the chocolate causing it to melt.

Explanation:

Conduction is the transfer of heat through touch.

Convection is the transfer of heat through liquid or gas.

Radiation is how heat/energy travels through space.

Hope this helped!

Answer:

the answer is B

Explanation:

Answer:

Explanation:

If another predator was introduced to this food web, this food web would fail because it won't be balanced well. Let's say the predator eats more food than the eagle. Then the eagle would have less food for itself, and it might go endangered, and vice versa if the eagle eats more. Either way, this would cause almost no worms left and that means there would be an overflow of the rats because there would be no worms for them to be eaten by. This would cause a shortage of crops as well.

I hope this made sense!

i think false because of the wind or insects

Answer:

5 L

Explanation:

We'll begin by calculating the molarity of the CaCl₂ solution. This can be obtained as follow:

Mole of CaCl₂ = 0.5 mole

Volume = 2 L

Molarity =?

Molarity = mole /Volume

Molarity = 0.5 / 2

Molarity = 0.25 M

Finally, we shall determine the volume of the diluted solution. This can be obtained as follow:

Molarity of stock solution (M₁) = 0.25 M

Volume of stock solution (V₁) = 2 L

Molarity of diluted solution (M₂) = 0.1 M

Volume of diluted solution (V₂) =?

M₁V₁ = M₂V₂

0.25 × 2 = 0.1 × V₂

0.5 = 0.1 × V₂

Divide both side by 0.1

V₂ = 0.5 / 0.1

V₂ = 5 L

Thus the volume of the diluted solution is 5 L

Answer:

Explain: In order to balance the chemical equation, you need to make sure the number of atoms of each element on the reactant side is equal to the number of atoms of each element on the product side. In order make both sides equal, you will need to multiply the number of atoms in each element until both sides are equal.

Genetic engineering improved the lives if individuals with insulin because it helps the body use and store sugar, since people with diabetes can't produce insulin.

Answer:

C.It remains at rest or moves at constant speed in the same direction.

Explanation:

First, remember the Newton's 1st law of motion which states that the object at rest will remain at rest and that in motion will stay in motion with the same speed and same direction unless acted by unbalance forces.

Balanced forces on an object occur when two forces at act on an object are equal in size and act in opposite direction. In this case, a stationary object will stay at  rest while an object moving will continue to move at the same speed and same direction.

An object acted by balanced forces is said to be at equilibrium, thus the state of motion will be maintained.The object will not accelerate. A good example of an object acted by balanced forces is an object at rest or in constant motion such as a car that stopped at red-light signal or a car travelling at a constant speed.

Answer:

1.) b

2.) c

3.) e

4.) g

5.) j

6.) k

HOPE THIS HELPS

-Todo <3

Explanation:

Answer:B, C, F, G, I, L.

Explanation: i think that these are the correct one there was not a whole lot of contects on the question

Answer:

See explanation

Explanation:

When we are writing chemical reaction equations, we must ensure that such equations are balanced. That is, the number of atoms of each element on both sides of the reaction equation are exactly the same.

After we identify the formula of each compound in the reaction, then we proceed the write the balanced reaction equation as follows;

CuCl2 + 2AgNO3 -------> Cu(NO3)2  + 2AgCl

Answer:

Carbon-12: with 6 protons and 6 neutrons and an atomic mass of 12.

Explanation:

1.Natural selection is the differential survival and reproduction of individuals due to differences in phenotype. It is a key mechanism of evolution, the change in the heritable traits characteristic of a population over generations. 

2.Because predators were able to spot the light moths more easily, the dark moths were more likely to survive and reproduce. ... The peppered moth case is an example of natural selection. In this case, changes in the environment caused changes in the characteristics that were most beneficial for survival

Answer:

D

Explanation:

31 / 2.8 = 11.0714286 L per mole of helium

3.5 / 4 = 0.875 moles

2.8 + 0.875 = 3.675 moles

11.0714286 x 3.675 = 40.6875 L

Answer:

B

Explanation:

I'm obsessed with me as much as you

Say you'd die for me I'd die for me too

And if I lost you I'd still have me I can't lose

When you say that you're obsessed with me, me too