Calculate the mass of magnesium needed to make 25g of magnesium oxide

Prisms separate ________ light, such as that from the Sun, by wavelength. Which best completes the statement? ultraviolet white

tatuchka [14]

Answer:

The answer is B white

Explanation:

hope it helps :)

4 0

2 years ago

Imagine you needed to identify if an object has undergone a physical change or a chemical change. What information would you nee

pishuonlain [190]

How it looks. basically the thing that tells you how it change. for example if an ice cube was melted (heat), it only changed physically not chemically as the h20 molecules are still there. however lets say you burn woos— you cant get that would back. its ash now and it has changed chemically.

7 0

2 years ago

In the adjoining figure, the circles with the + sign represent protons and the empty circles represent neutrons. Determine which

Natali [406]

Answer: option C. 2 and 3.

Explanation:

1) Isotopes are atoms of a same element with different number of neutrons. That means that the isotopes of a same element have the same number of protons, since the number of protons is what identify an element.

2) For example, all the atoms of oxygen have 8 protons. But isotope oxygen-16 has 8 neutrons, while oxygen-18 has 10 neutrons.

3) In the figure there are 3 different atoms:

i) atom # 1 has 5 protons and 7 neutrons

ii) atom # 2 has 6 protons and 7 neutrons

iii) atom # 3 has 6 protons and 8 neutrons.

4) Hence the atoms with the same number of protons and different number of neutrons are the #2 and the # 3. So, they are the isotopes of the same element.

4 0

2 years ago

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Determine the y component of reaction at a using scalar notation. express your answer to three significant figures and include t

blagie [28]

In order to compute the y-component of a vector, we simply use the formula:

Fy = F*sin(∅)
Where ∅ is the angle of the vector measured from the positive x-axis and F is the magnitude of the vector.

Similarly, the x-component is calculated by substituting sin(∅) with cos(∅)

6 0

2 years ago

Percentage yield of sodium peroxide if 5 g of sodium oxide produces 5.5 g of sodium peroxide

Rama09 [41]

<h3>Answer:</h3>

87.40 %

<h3>Explanation:</h3>

Concept being tested: Percent yield of a product

We are given;

Mass of Sodium oxide 5 g

Experimental or Actual yield of sodium peroxide IS 5.5 g

We are required to calculate the percent yield of sodium peroxide;

The equation for the reaction that forms sodium peroxide is

2Na₂O + O₂ → 2Na₂O₂

<h3>Step 1; moles of sodium oxide</h3>

Moles = mass ÷ molar mass

Molar mass of sodium oxide is 61.98 g/mol

Therefore;

Moles = 5 g ÷ 61.98 g/mol

= 0.0807 moles

<h3>Step 2: Theoretical moles of sodium peroxide produced </h3>

From the equation, 2 moles of sodium oxide produces 1 mole of sodium peroxide.

Thus, moles of sodium peroxide used is 0.0807 moles

<h3>Step 3: Theoretical mass of sodium peroxide used</h3>

Mass = Number of moles × Molar mass

Molar mass of sodium peroxide = 77.98 g/mol

Therefore;

Theoretical mass = 0.0807 moles × 77.98 g/mol

= 6.293 g

Theoretical mass of Na₂O₂ is 6.293 g

<h3>Step 4: Percent yield of Na₂O₂</h3>

We know that percent yield is given by the ratio of actual yield to theoretical yield expressed as a percentage.

$Percent yield=(\frac{Actual yield}{theoretical yield})100$

$Percent yield(Na_{2}O_{2})=(\frac{5.5g}{6.293g})100$

= 87.40 %

Therefore, the percentage yield of sodium peroxide is 87.4%

8 0

2 years ago

Calculate the mass of magnesium needed to make 25g of magnesium oxide​

Calculate the mass of magnesium needed to make 25g of magnesium oxide