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3 years ago

How would you decrease the mass number?

Chemistry

2 answers:

iragen [17]3 years ago

7 0

Answer:

Protons are positively charged. When a nucleus emits an alpha particle, these changes happen: the mass number decreases by 4. the atomic number decreases by 2.

Explanation:

Galina-37 [17]3 years ago

4 0

Protons are positively charged. When a nucleus emits an alpha particle, these changes happen: the mass number decreases by 4. the atomic number decreases by 2.

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what is a major drawback of using fossil fuels they warmn the planet they contain no greenohuse gases

Charra [1.4K]

The major drawback of fossil fuels is that they warm the planet i.e. they cause global warming.

The reaction typically gives off heat and light as well. The general equation for a complete combustion reaction is:

Fuel + O2 → CO2 + H2O + ENERGY

<h3>Disadvantages of Fossil fuels</h3>

The term "fossil fuels" refers to flammable organic geologic formations, including dead organic matter that has been buried hundreds of feet beneath sediment.

Fossil fuel emissions include various oxides, such as carbon, nitrogen, and sulfate, which cause acid rain and harm the soil's fertility and water quality.
Both coal and petroleum burning discharge a significant amount of pollutants into the atmosphere, contributing to pollution levels.
Gases like carbon dioxide are released through the burning of fossil fuels, which aids in climate change.

To view similar questions on Fossil fuels, refer to:

brainly.com/question/14339391

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7 0

1 year ago

A 0.964 gram sample of a mixture of sodium formate and sodium chloride is analyzed by adding sulfuric acid. The equation for the

frosja888 [35]

Answer: 67.8 %.

Explanation:

Okay, let us delve right into the solution to the question;

The balanced chemical reaction is given by the equation (1) below;

2 HCOONa + H2SO4 ---------> 2 CO + 2 H2O + Na2SO4. ----------------------------------------------------------------------------(1).

From the balanced chemical reaction in equation (1) above we can see that; 2 moles of HCOONa reacts with one moles of tetraoxosulphate acid, H2SO4 to produce 2 moles of carbonmonoxide,CO; 2 moles of water, H2O and 1 mole of sodium tetraoxosulphate, Na2SO4.

The parameters given from the question are; total atmospheric pressure, P(t) = 752 torr, volume of CO= 242 mL = 0.242 Litres.

STEP ONE : find the carbon monoxide,CO pressure; P(CO).

Using the formula below;

P(t) = P(CO) + P(H2O). Hence;

P(CO) = P(t) - P(H2O). Note that P(H2O)= 19.8 torr.

==>P(CO)= 752 torr - 19.8 torr = 732.2 torr.

STEP TWO: calculate the number of moles of Carbonmonoxide,CO.

Using the formula below;

Number of moles= pressure(P) × volume(v) / gas constant(R) × temperature (T).

That is, n= PV/RT.

n= 732 torr × 0.242 Litres/ 62.4 × 295.15.

= 9.62 × 10^-3 mol of CO.

STEP THREE:

2 moles of HCOONa = 2 moles of CO.

=> 2 moles of HCOONa = 2 moles of CO/ 2 moles of CO = 1 mol( HCOONa/ CO).

Then, 9.62 × 10^-3 mol of CO × 1 mol( HCOONa/ CO).

==> 9.62 × 10^-3 mol HCOONa × molar masss of HCOONa(68 grams/mol)

= 0.654 grams.

Therefore, the percentage of sodium formate in the original mixture = 0.654 grams/ 0.964 gram × 100 = 67.8 %.

5 0

3 years ago

The rate law for the decomposition of phosphine () is It takes 135. s for 1.00 M to decrease to 0.250 M. How much time is requir

vova2212 [387]

Answer:

189.71 secs

Explanation:

We know that decomposition is a first order reaction;

So;

ln[A] = ln[A]o - kt

But;

[A]o = 1.00 M

[A] = 0.250 M

t =135 s

Hence;

ln[A] - ln[A]o = kt

k = ln[A] - ln[A]o/t

k = ln(1) - ln(0.250)/135

k =0 - (-1.386)/135

k = 1.386/135

k= 0.01

So time taken now will be;

ln[A] - ln[A]o = kt

t = ln[A] - ln[A]o/k

t = ln (3) - ln(0.450)/0.01

t = 1.0986 - (-0.7985)/0.01

t = 1.0986 + 0.7985/0.01

t = 189.71 secs

8 0

2 years ago

What fraction of a Sr-90 sample remains unchanged after 87.3 years

jolli1 [7]

The answer is 1/8.

Half-life is the time required for the amount of a sample to half its value.
To calculate this, we will use the following formulas:
1. $(1/2)^{n} = x$ ,
where:
n - a number of half-lives
x - a remained fraction of a sample

2. $t_{1/2} = \frac{t}{n}$
where:
 $t_{1/2}$ - half-life
t - total time elapsed
n - a number of half-lives

The half-life of Sr-90 is 28.8 years.
So, we know:
t = 87.3 years
 $t_{1/2}$ = 28.8 years

We need:
n = ?
x = ?

We could first use the second equation, to calculate n:
If:
$t_{1/2} = \frac{t}{n}$ ,
Then:
$n = \frac{t}{ t_{1/2} }$
⇒ $n = \frac{87.3 years}{28.8 years}$
⇒ $n=3.03$
⇒ n ≈ 3

Now we can use the first equation to calculate the remained amount of the sample.
 $(1/2)^{n} = x$
⇒ $x=(1/2)^3$
⇒ $x= \frac{1}{8}$

8 0

3 years ago

Express the following in liters at STP: 6.62 x 10-3 moles HF

serious [3.7K]

Answer:

The volume of 6.62×10⁻³moles of HF at STP is 148.38×10⁻³ L

Explanation:

Given data:

Number of moles of HF = 6.62×10⁻³ mol

Volume of HF in litter at STP = ?

Solution:

The given problem will be solve by using general gas equation,

PV = nRT

P= Pressure

V = volume

n = number of moles

R = general gas constant = 0.0821 atm.L/ mol.K

T = temperature in kelvin

Standard temperature = 273 K

Standard pressure = 1 atm

Now we will put the values in formula.

1 atm × V = 6.62×10⁻³mol ×0.0821 atm.L/ mol.K × 273 K

V = 6.62×10⁻³mol ×0.0821 atm.L/ mol.K × 273 K / 1 atm

V = 148.38×10⁻³ L

Thus, the volume of 6.62×10⁻³moles of HF at STP is 148.38×10⁻³ L.

8 0

3 years ago