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2 years ago

Can someone help please? :)

Chemistry

1 answer:

Leno4ka [110]2 years ago

7 0

1) This is a definition.

2) Protons are given by the bottom number (since atomic number = number of protons).

3) Neutrons = (mass number)-(atomic number), which are the top and bottom numbers, respectively.

4) Nuclear fusion involves combining two things together, which is only reflected by the last option.

5) This is a fact.

6) This is a fact.

7) This is a fact.

8) This is a fact.

9) The correct option is the explanation.

You might be interested in

When aqueous solutions of K3PO4 and Ba(NO3)2 are combined, Ba3(PO4)2 precipitates. Calculate the mass, in grams, of the Ba3(PO4)

Firdavs [7]

Answer:

Mass of Ba₃(PO₄)₂ = 0.0361 g

Explanation:

Given data:

Volume of Ba(NO₃)₂ = 1.2 mL (1.2 × 10⁻³ L )

Molarity of Ba(NO₃)₂ = 0.152 M

Volume of K₃PO₄ = 4.2 mL (4.2 × 10⁻³ L)

Molarity of K₃PO₄ = 0.604 M

Mass of Ba₃(PO₄)₂ produced = ?

Solution:

Chemical equation:

3Ba(NO₃)₂ + 2K₃PO₄ → Ba₃(PO₄)₂ + 6KNO₃

Number of moles of Ba(NO₃)₂ = Molarity × Volume in litter

Number of moles of Ba(NO₃)₂ = 0.152 M × 1.2 × 10⁻³ L

Number of moles of Ba(NO₃)₂ = 0.182 × 10⁻³ mol

Number of moles of K₃PO₄ = Molarity × Volume in litter

Number of moles of K₃PO₄ = 0.604 M × 4.2 × 10⁻³ L

Number of moles of K₃PO₄ = 2.537 × 10⁻³ mol

Now we will compare the moles of Ba₃(PO₄)₂ with K₃PO₄ and Ba(NO₃)₂ .

Ba(NO₃)₂ : Ba₃(PO₄)₂

3 : 1

0.182 × 10⁻³ : 1/3 ×0.182 × 10⁻³ = 0.060 × 10⁻³ mol

K₃PO₄ : Ba₃(PO₄)₂

2 : 1

2.537 × 10⁻³ : 1/2 × 2.537 × 10⁻³= 1.269 × 10⁻³ mol

The number of moles of Ba₃(PO₄)₂ produced by Ba(NO₃)₂ are less it will limiting reactant.

Mass of Ba₃(PO₄)₂ = moles × molar mass

Mass of Ba₃(PO₄)₂ = 0.060 × 10⁻³ mol × 601.93 g/mol

Mass of Ba₃(PO₄)₂ = 36.12 × 10⁻³ g

Mass of Ba₃(PO₄)₂ = 0.0361 g

6 0

3 years ago

A steam engine (assume a Carnot engine ) has an efficiency of 50.8%. If the waste heat has a temperature of 72.4 ◦C, what is the

Inessa05 [86]

Answer:

The temperature of the boiler is approximately 147.1 °C

Explanation:

A Carnot engine is an ideal engine that has the highest efficiency among all the engines because the second law of thermodynamics.That efficiency $\eta$ is:

$\eta=1-\frac{T_{c}}{T_{h}}$

with $T_{h}$ the temperature of the hot reservoir (the boiler temperature) and $T_{c}$ the temperature of the cold reservoir (the steam temperature). Solving for $T_{h}$ :

$T_{h}=\frac{-T_{c}}{\eta-1}=\frac{-72.4}{0.508-1}\approx147.1\,C$

3 0

2 years ago

Show All Work For Brainliest

sattari [20]

Answer:

1) 16.8 L CO2

2) 36.96 L NH3

3) 9.88 L CO2

4) 56.99 L H2O

Explanation:

How many liters of carbon dioxide gas will be produced when 75.0 g of calcium carbonate decomposes to form calcium oxide when at STP?

CaCO3 → CaO + CO2

Moles calcium carbonate = 75.0 grams / 100.09 g/mol

Moles calcium carbonate = 0.750 moles

For 1 mol CaCO3 we'll have 1 mol CaO and 1 mol CO2

For 0.750 moles CaCO3 we'll have 0.750 moles CO2

1 mol = 22.4 L

0.750 moles CO2 = 0.750 *22.4 L = 16.8 L CO2

2. Hydrogen gas reacts with 23.1 g of nitrogen gas to produce ammonia (NH3). What volume of ammonia will be produced at STP?

3H2 + N2 → 2NH3

Moles N2 = 23.1 grams / 28.0 g/mol

Moles N2 = 0.825 moles

For 3 moles H2 we need 1 mol N2 to produce 2 moles NH3

For 0.825 moles N2 we'll have 2*0.825 = 1.65 moles NH3

1 mol = 22.4 L

1.65 mol = 1.65 * 22.4 L = 36.96 L NH3

3. Iron (III) oxide reacts with carbon monoxide to form iron and carbon dioxide. How many liters of carbon dioxide will be produced from 23.5 g of iron (III) oxide when at STP?

Fe2O3 + 3CO → 2Fe + 3CO2

Moles Fe2O3 = 23.5 grams / 159.69 g/mol

Moles Fe2O3 = 0.147 moles

For 1 mol Fe2O3 we need 3 moles CO to produce 2 moles Fe and 3 moles CO2

For 0.147 moles Fe2O3 we'll have 3*0.147 = 0.441 moles CO2

1 mol = 22.4 L

0.441 moles = 22.4 * 0.441 = 9.88 L CO2

4.How many liters of water vapor would be produced in the combustion of 12.5L of ethane, C2H6 at STP?

2C2H6 + 7O2 →4CO2 + 6H2O

22.4 L = 1 mol

12.5 L = 0.848 moles C2H6

For 2 moles C2H6 we need 7 moles O2 to produce 4 moles CO2 and 6 moles H2O

For 0.848 moles C2H6 we'll have 3*0.848 = 2.544 moles H2O

1 mol = 22.4 L

2.544 moles = 22.4 L * 2.544 = 56.99 L H2O

5 0

3 years ago

What is bias in an experiment?

N76 [4]

○ c. ○

◘

because a Research bias, also called experimenter bias, is a process where the scientists performing the research influence the results, in order to portray a certain outcome.

◘

hope that helped ♥

3 0

3 years ago

What volume of H2 at STP, can be released by 42.7 g Zn in the equation: Zn + 2 HCl ————> H2 + ZnCl2

ehidna [41]

Answer:

0.86L.

Explanation:

1mol of Zn has mass of 65.39g . The amount of Zn is 2.5g65.39g/mol=0.038mol

7 0

2 years ago