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3 years ago

8TH GRADE SCIENCE PLEASE HELP‼️‼️‼️‼️‼️

Chemistry

1 answer:

ANEK [815]3 years ago

4 0

Answer:

B or C, im not 100 % sure.

Explanation:

draw out the oh scale, then place all the subtances on the number line, then you will see which statement are correct and which are not.

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What what is the equation for percent error

Stella [2.4K]

When you calculate results that are aiming for known values, the percent error formula is useful tool for determining the precision of your calculations. The formula is given by: The experimental value is your calculated value, and the theoretical value is your known value.

5 0

2 years ago

A 2.89 g sample of a metal chloride, MCl2, is dissolved in water and treated with excess aqueous silver nitrate. The silver chlo

dsp73

Answer:

58.0 g/mol

Explanation:

The reaction that takes place is:

MCl₂ + 2AgNO₃ → 2AgCl + M(NO₃)₂

First we calculate how many moles of silver chloride were produced, using its molar mass:

6.41 g AgCl ÷ 143.32 g/mol = 0.0447 mol AgCl

Then we convert AgCl moles into MCl₂ moles, using the stoichiometric ratio:

0.0447 mol AgCl * $\frac{1molMCl_2}{2molAgCl}$ = 0.0224 mol MCl₂

Now we calculate the molar mass of MCl₂, using the original mass of the sample:

2.86 g / 0.0224 mol = 127.68 g/mol

We can write the molar mass of MCl₂ as:

Molar Mass MCl₂ = Molar Mass of M + (Molar Mass of Cl)*2

127.68 g/mol = Molar Mass of M + (35.45 g/mol)*2

Finally we calculate the molar mass of M:

Molar Mass of M = 57 g/mol

The closest option is 58.0 g/mol.

6 0

2 years ago

Calculate the mass of ammonia (NH3) that contains a billion (1.00 * 10^12) hydrogen atoms.

Lynna [10]

Answer:

The mass of ammonia (NH3) that contains $1.00 \times 10^12$ hydrogen atoms is $9.4\times 10^{-12}$ g.

Explanation:

As $6.022\times 10^{23}$ atoms of hydrogen = 1 mole of the hydrogen atom

Therefore, $10^{12}$ atoms of hydrogen $= \frac{1}{6.022 \times 10^{23}}\times 10^{12}=1.66\times 10^{-12}$ moles of the hydrogen atom.

Now, there are 3 moles of hydrogen atoms in 1 mole of ammonia $(NH_3)$ .

As the mass of 1 mole of ammonia is 17g, so

when there are 3 moles of hydrogen atoms, then the mass of ammonia = 17 g

Therefore, when there are $1.66\times 10^{-12}$ moles of hydrogen atoms, then the mass of ammonia $= \frac{17}{3}\times 1.66\times 10^{-12}=9.4\times 10^{-12$ g.

Hence, the mass of ammonia $(NH_3)$ that contains $1.00 \times 10^12$ hydrogen atoms is $9.4\times 10^{-12}$ g.

3 0

3 years ago

Which of the following is a monatomic anion? a) NH4+ b) Fr+ c) SO42– d) F-

Y_Kistochka [10]

I think that it's d) F- but I'm not sure.

8 0

3 years ago

Read 2 more answers

Which area should have the lowest temperatures? A. 1 B.2 C.3 D.4

pochemuha

Answer:

A. 1

Explanation:

The higher you get in the atmosphere the cooler the temperature will be. The reason it's actually colder is because, as you go up in the atmosphere, the Earth's atmosphere feels less pressure the higher up you go. So as the gas in the atmosphere rises it feels less pressure, which makes it expand.

Hope this Help :)

Please mark brainliest :D

7 0

2 years ago