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3 years ago

Which phrase best describes igneous rock

Chemistry

2 answers:

kozerog [31]3 years ago

5 0

Answer: a

Explanation:

Luden [163]3 years ago

4 0

Forms when lava and magma cool (A)

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The amount ofcalcium present in milk can be determined by adding oxalate to asample and measuring the massof calcium oxalate pre

Sauron [17]

Answer: The mass percent of calcium in milk is 0.107 %

Explanation:

To calculate the number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$ .....(1)

Given mass of calcium oxalate = 0.429 g

Molar mass of calcium oxalate = 128.1 g/mol

Putting values in equation 1, we get:

$\text{Moles of calcium oxalate}=\frac{0.429g}{128.1g/mol}=0.0033mol$

The given chemical equation follows:

$Na_2C_2O_4(aq.)+Ca^{2+}(aq.)\rightarrow CaC_2O_4(s)+2Na^+(aq.)$

Sodium oxalate is present in excess. So, it is considered as an excess reagent. And, calcium ion is a limiting reagent because it limits the formation of product.

By Stoichiometry of the reaction:

1 mole of calcium oxalate is produced from 1 mole of calcium ion

So, 0.0033 moles of calcium oxalate is produced from = $\frac{1}{1}\times 0.0033=0.0033mol$ of calcium ions

Now, calculating the mass of calcium ions by using equation 1, we get:

Moles of calcium ions = 0.0033 moles

Molar mass of calcium ions = 40 g/mol

Putting values in equation 1, we get:

$0.0033mol=\frac{\text{Mass of calcium ions}}{40g/mol}\\\\\text{Mass of calcium ions}=(0.0033mol\times 40g/mol)=0.132g$

To calculate the mass percentage of calcium ions in milk, we use the equation:

$\text{Mass percent of calcium ions}=\frac{\text{Mass of calcium ions}}{\text{Mass of milk}}\times 100$

Mass of milk = 125 g

Mass of calcium ions = 0.132 g

Putting values in above equation, we get:

$\text{Mass percent of calcium ions}=\frac{0.132g}{125g}\times 100=0.107\%$

Hence, the mass percent of calcium in milk is 0.107 %

7 0

3 years ago

Which group would Ns2np2 go into

FrozenT [24]

Answer:

The group 15 elements: the pnicogens

Explanation:

The group 15 elements, nitrogen, phosphorus, arsenic, antimony and bismuth, all have the general valence shell electronic configuration ns2np3. They can all exist in the +3 or +5 oxidation state, with the +3 state increasing in stability as we move vertically down the group.

3 0

3 years ago

Read 2 more answers

I need help with this question please Chemistry

ivolga24 [154]

I cannot see it can you make it bigger by any chance dm me on Instagram

5 0

3 years ago

Why B-Cl bond is polar?

aniked [119]

Answer:

The difference in the electronegativities of chlorine and boron is 3.0 - 2.0 = 1.0 ; the difference in between chlorine and carbon is 3.0 = 2.5 = 0.5 . Consequently, the B-Cl bond is more polar ; the chlorine atom asrries the partial negative charge because it has higher electronegativity .

Explanation:

hope it helps!

8 0

3 years ago

Read 2 more answers

In the following reaction, how many grams of NaBr will react with 311 grams of Pb(NO3)2?

Mashutka [201]

Molar mass :

NaBr = 103 g/mol

Pb(NO3)2 = 331.20 g/mol

Balanced chemical equation :

2 NaBr + 1 Pb(NO3)2 = 2 NaNO3 + 1 PbBr2

2*103 g NaBr ------------> 1 * 331.20 g Pb(NO3)2
g NaBr -------------------> 311 g Pb(NO3)2

331.20 g = 2*103*311

331.20 g = 64066

mass ( NaBr ) = 64066 / 331.20

mass ( naBr) = 193,43 g of NaBr

hope this helps!.

5 0

3 years ago