How many moles are in 564 grams of copper

Why do Man holes(road) build by use only circular type??

sashaice [31]

Answer: Manholes are usually round, primarily because roundness is the best shape to resist the compression of the earth; covers are round because they are easier to manufacture than square or rectangular shapes, they are easier to move by rolling, and they can't fall into the opening.

Explanation:

7 0

3 years ago

General Chemistry fourth edition by McQuarrie, Rock, and Gallogly. University Science Books presented by Macmillan Learning.

Helen [10]

Answer:

3.07 Cal/g

Explanation:

Step 1: Calculate the heat absorbed by the calorimeter

We will use the following expression.

Q = C × ΔT

where,

Q: heat absorbed

C: heat capacity of the calorimeter (37.60 kJ/K = 37.60 kJ/°C)

ΔT: temperature change (2.29 °C)

Q = 37.60 kJ/°C × 2.29 °C = 86.1 kJ

According to the law of conservation of energy, the heat released by the candy has the same magnitude as the heat absorbed by the calorimeter.

Step 2: Convert 86.1 kJ to Cal

We will use the conversion factor 1 Cal = 4.186 kJ.

86.1 kJ × 1 Cal/4.186 kJ = 20.6 Cal

Step 3: Calculate the number of Cal per gram of candy

20.6 Cal/6.70 g = 3.07 Cal/g

3 0

3 years ago

Shari is trying to determine how music affects a person’s pulse rate. She has her mother listen to classic rock at a high volume

olchik [2.2K]

a specific hypothesis to test with a controlled experiment

6 0

3 years ago

Read 2 more answers

Hard water often contains dissolved Ca2+ and Mg2+ ions. One way to soften water is to add phosphates. The phosphate ion forms in

avanturin [10]

<span>5.5×10−2M in calcium chloride and 8.0×10−2M in magnesium nitrate.
What mass of sodium phosphate must be added to 1.5L of this solution to completely eliminate the hard water ion

1) Content of Ca (2+) ions

Calcium chloride = CaCl2

Ionization equation: CaCl2 ---> Ca (2+) + 2 Cl (-)

=> Molar ratios: 1 mol of CaCl2 : 1 mol Ca(2+) : 2 mol Cl(-)

Calculate the number of moles of CaCl2 in 1.5 liters of 5.5 * 10^-2 M solution

M = n / V => n = M*V = 5.5 * 10^ -2 M * 1.5 l = 0.0825 mol CaCl2

=> 0.0825 mol Ca(2+)

2) Number of phosphate ions needed to react with 0.0825 mol Ca(2+)

formula of phospahte ion: PO4 (3-)

molar ratio: 2PO4(3-) + 3Ca(2+) = Ca3 (PO4)2

Proportion: 2 mol PO4(3-) / 3 mol Ca(2+) = x / 0.0825 mol Ca(2+)

=> x = 0.0825 coml Ca(2+) * 2 mol PO4(3-) / 3 mol Ca(2+) = 0.055 mol PO4(3-)

3) Content of Mg(2+) ions

Ionization equation: Mg (NO3)2 ----> Mg(2+) + 2 NO3 (-)

Molar ratios: 1 mol Mg(NO3)2 : 1 mol Mg(2+) + 2 mol NO3(-)

number of moles of Mg(NO3)2 in 1.5 liter of 8.0 * 10^-2 M solution

n = M * V = 8.0 * 10^ -2 M * 1.5 liter = 0.12 moles Mg(NO3)2

ions of Mg(2+) = 0.12 mol Mg(NO3)2 * 1 mol Mg(2+) / mol Mg(NO3)2 = 0.12 mol Mg(2+)

4) Number of phosphate ions needed to react with 0.12 mol Mg(2+)

2PO4(3-) + 3Mg(2+) = Mg3(PO4)2

=> 2 mol PO4(3-) / 3 mol Mg(2+) = x / 0.12 mol Mg(2+)

=> x = 0.12 * 2/3 mol PO4(3-) = 0.16 mol PO4(3-)

5) Total number of moles of PO4(3-)

0.055 mol + 0.16 mol = 0.215 mol

6) Sodium phosphate

Sodium phosphate = Na3(PO4)

Na3PO4 ---> 3Na(+) + PO4(3-)

=> 1 mol Na3PO4 : 1 mol PO4(3-)

=> 0.215 mol PO4(3-) : 0.215 mol Na3PO4

mass in grams = number of moles * molar mass

molar mass of Na3 PO4 = 3*23 g/mol + 31 g/mol + 4*16 g/mol = 164 g/mol

=> mass in grams = 0.215 mol * 164 g/mol = 35.26 g

Answer: 35.26 g of sodium phosphate
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5 0

4 years ago

What are the chemical properties of beryllium phosphide??

o-na [289]

Answer:

Forms ionic bonds, insoluble, doesn't participate in single or double displacement reactions, non-reactive, high heat of combustion

Explanation:

Beryllium is a metal, since it belongs to group 2A, the alkaline earth metals. It has a total of 2 valence electrons.

Phosphorus, on the other hand, belongs to group 5A and has a total of 5 valence electrons.

We have a compound which has a metal in it, therefore, it's an ionic compound. Beryllium, our metal, loses its 2 electrons to gain an octet and phosphorus, our nonmetal, should gain 3 electrons to have an octet. The oxidation states are +2 and -3 respectively. This means we need 3 beryllium cations and 2 phosphide anions in our formula $Be_3P_2$ .

Beryllium phosphide would be expected to be insoluble, as only beryllium chloride, fluoride, nitrate, phosphate and sulfate are soluble substances, while the remaining ones are expected to be insoluble.

Due to its insolubility, beryllium phosphide would not participate in any ionic reactions, such as single displacement or double displacement.

Since it's insoluble, we expect this compound to be chemically stable and not reactive. This implies that if we wanted to burn it, the heat of combustion would be very high, as a lot of energy would be needed to be supplied in an endothermic reaction in order to burn it.

8 0

3 years ago