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3 years ago

Which step you should take before performing a scientific investigation

Chemistry

1 answer:

Julli [10]3 years ago

4 0

Answer:

D. Purchase the equipment and chemicals you will need

Explanation:

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At a festival, spherical balloons with a radius of 170.cm are to be inflated with hot air and released. The air at the festival

MissTica

Answer:

The correct answer is 1.5 balloons.

Explanation:

Based on the given question, the radius of the spherical balloons is 170 cm. Therefore, the volume of each balloon will be,

= 4/3 × π × (170)³ cm³

= 20.5176 × 10⁶ cm³

= 20.5176 m³

The density of air at 100 degree C s 0.946 Kg m⁻³

The mass of air in each balloon can be calculated by using the formula,

Mass = density × volume

Mass = 0.946 Kg m⁻³ × 20.5176 m³

Mass = 19.410 Kg

The heat energy, that is, required to bring the air from 25 degree C to 100 degree C will be,

= 19.410 × 10³ g × (100 -25) degree C × 1.009 J/g degree C

= 14.68 × 10⁵ J

The concentration of butane given is 1.00 Kg or 1000 g

The molecular weight of butane is 58.12 g per mole

The moles or n can be calculated by using the formula,

n = mass / mol.wt

n = 1000 g/58.12 g/mol = 17.20 mol

The formation of enthalpy of butane at 25 degree C is 125.7 × 10³ J/mol. The evolution of heat energy that take place at the time of burning 17.20 moles of butane is,

= 125.7 × 10³ J/mol × 17.20 mol

= 2.16 × 10⁶ J

The number of balloons that can be inflated with hot air is,

= 2.16 × 10⁶ J / 14.68 × 10⁵ J per each balloon

= 1.5 balloons

Hence, maximum of 1.5 balloons can be inflated.

7 0

3 years ago

Charles is given two electrical conductors – aluminium and graphite. Help him to select one for making an electric wire. Justify

Iteru [2.4K]

Answer: aluminum I think

Explanation:

6 0

3 years ago

Need help answering

svp [43]

Answer:

Your answer would be E

Explanation:

4 0

2 years ago

How to tell the difference between polar and nonpolar covalent bonds?

NemiM [27]

You need to look at the electronegativity and decide wheter the difference of both of the numbers are significant enough to form a polar bond

3 0

3 years ago

Write 2,469,100 in Engineering Notation with 3 significant figures.

Gala2k [10]

Answer: $2.47\times 10^{6}$

Explanation:

Engineering notation : It is the representation of expressing the numbers that are too big or too small and are represented in the decimal form times 10 raise to the power. It is similar to the scientific notation but in engineering notation, the powers of ten are always multiples of 3.

The engineering notation written in the form:

$a\times 10^b$

where,

a = the number which is greater than 0 and less than 999

b = an integer multiple of 3

Now converting the given value of 2,469,100 into engineering notation, we get $2.47\times 10^{6}$

Hence, the correct answer is, $2.47\times 10^{6}$

6 0

3 years ago