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Alex73 [517]
3 years ago
15

Need help with 7,9 and may you check my answer for 8 to ?

Chemistry
2 answers:
fomenos3 years ago
8 0
8 looks right to me but not 100%
steposvetlana [31]3 years ago
7 0
Number 9 is C because they are the same element but different numbers. Number 8 is B because they are isotopes of each other, and isotopes have varying number of protons (that’s what make them isotopes of each other.) Number 7 is B.
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Nault 25000L 250 our = 25000L 15040 8. How many grams of CaCl2 are needed to make 150.0 mL of a 0.500 M CF solution? (Note: CaCl
yuradex [85]

Answer:

You need 8,324 g of CaCl₂ yo make this solution

Explanation:

Molarity is a way to express concentration in a solution, in units of moles of solute per liter of solution.

To know the grams of CaCl₂ it is necessary to know, first, the moles of this substance with the desired volume and concentration , thus:

0,1500 L × \frac{0,500 mol}{L} = 0,075 CaCl₂ moles

Now, with the molar mass of CaCl₂ you will obtain the necessary grams, thus:

0,075 CaCl₂ moles  × \frac{110,98 g}{mol} = 8,324 g of CaCl₂

So, you need <em>8,324 g of CaCl₂</em> to make 150,0 mL of a 0,500M solution

I hope it helps!

3 0
3 years ago
PLEASE HELP!!!!! I need help with this question!
Ivahew [28]

Answer:

Exothermic Reaction

Explanation:

Its a combustion reaction and they are always exothermic in nature.

8 0
2 years ago
Convert the following with the correct number of significant figures:
larisa [96]

Answer:

1.78 × 10⁹ μg

Explanation:

We have to convert 1.78 kg to μg.

Step 1: Convert 1.78 kilograms to grams

We will use the conversion factor 1 kg = 10³ g.

1.78 kg × 10³ g/1 kg = 1.78 × 10³ g

Step 2: Convert 1.78 × 10³ grams to micrograms

We will use the conversion factor 1 g = 10⁶ μg.

1.78 × 10³ g × 10⁶ μg/1 g = 1.78 × 10⁹ μg

8 0
2 years ago
The cation that has the same number of electrons (isoelectronic) as Ne is
larisa [96]
Ne is isoelectronic with Na+ ion.
4 0
3 years ago
How do you make molecular equations a balanced iconic.
asambeis [7]
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</span><span><span>arate the net ionic equation into the two half-reactions. This means identifying and separating the reaction into an oxidation half-reaction and a reduction half-reaction. </span><span>For one of the half-reactions, balance the atoms except for O and H. You want the same number of atoms of each element on each side of the equation. </span><span>Repeat this with the other half-reaction. </span><span>Add H2O to balance the O atoms. Add H+ to balance the H atoms. The atoms (mass) should balance out now. </span><span>Now balance charge. Add e- (electrons) to one side of each half-reaction to balance charge. You may need to multiply the electrons the the two half-reactions to get the charge to balance out. It's fine to change coefficients as long as you change them on both sides of the equation. </span><span>Now, add the two half-reactions together. Inspect the final equation to make sure it is balanced. Electrons on both sides of the ionic equation must cancel out. </span><span>Double-check your work! Make sure there are equal numbers of each type of atom on both sides of the equation. Make sure the overall charge is the same on both sides of the ionic equation. </span><span>If the reaction takes place in a basic solution, add an equal number of OH- as you have H+ ions. Do this for both sides of the equation and combine H+ and OH- ions to form H2O. </span><span>Be sure to indicate the state of each species. Indicate solid with (s), liquid for (l), gas with (g), and aqueous solution with (aq). </span><span>Remember, a balanced net ionic equation only describes chemical species that participate in the reaction. Drop additional substances from the equation.ExampleThe net ionic equation for the reaction you get mixing 1 M HCl and 1 M NaOH is:H+(aq) + OH-(aq) → H2O(l)Even though sodium and chlorine exist in the reaction, the Cl- and Na+ ions are not written in the net ionic equation because they don't participate in the reaction.</span></span>
4 0
3 years ago
Read 2 more answers
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