How many significant figures are in the measurement 0.0030010 kilograms?

What is the name of the binary compound that has the formula k2s?

kozerog [31]

Potassium sulfide, also known as dipotassium monosulfide, consists of two potassium ions bonded to a sulfide atom, rendering the chemical formula K2S.Rarely found in nature due to its high reactivity with water, potassium sulfide is refined from the more common potassium sulfate (K2SO4) and is used in many industries

8 0

2 years ago

A mileage test is conducted for a new car model. Thirty randomly selected cars are driven for a month and the mileage is measure

Leni [432]

Answer: $(27.81,\ 29.39)$

Explanation:

Given : Sample size : n= 30 , it means it is a large sample (n≥ 30), so we use z-test .

Significance level : $\alpha: 1-0.95=0.05$

Critical value: $z_{\alpha/2}=1.96$

Sample mean : $\overline{x}=28.6$

Standard deviation : $\sigma=2.2$

The formula to find the confidence interval is given by :-

$\overline{x}\pm z_{\alpha/2}\dfrac{\sigma}{\sqrt{n}}$

i.e. $28.6\pm (1.96)\dfrac{2.2}{\sqrt{30}}$

i.e. $28.6\pm 0.787259889321$

$\approx28.6\pm 0.79=(28.6-0.79,28.6+0.79)=(27.81,\ 29.39)$

Hence, the 95% confidence interval for the mean mpg in the entire population of that car model = $(27.81,\ 29.39)$

4 0

3 years ago

Relative to electrons and electron states, what does each of the four quantum numbers specify

Alla [95]

Answer:

(n, l, m sub l, m sub s)

N: principle quantum number (1,2,3,4,etc)

l: angular momentum quantum number, the shape (l has to be at least 1 less than n, but can be 0 depending on n)

M sub l: magnetic quantum number (l determines this number)

M sub s: spin quantum number (can only ever be 1/2 or -1/2)

Explanation:

8 0

2 years ago

Rank the compounds in each set in order of increasing acid strength.

Viktor [21]

Answer:

See explanation

Explanation:

For this question, we have to remember the effect of an atom with high electronegativity as "Br". If the "Br" atom is closer to the carboxylic acid group (COOH) we will have an inductive effect. Due to the electronegativity of Br, the electrons of the C-H bond would be to the Br, then this bond would be weaker and the compound will be more acid (because is easier to produce the hydronium ion $H^+$ ).

With this in mind, for A in the last compound, we have 2 Br atoms near to the acid carboxylic group, so, we will have a high inductive effect, then the C-H would be weaker and we will have more acidity. Then we will have the compound with only 1 Br atom and finally, the last compound would be the one without Br atoms.

In B, the difference between the molecules is the position of the "Br" atom in the molecule. If the Br atom is closer to the acid group we will have a higher inductive effect and more acidity.

See figure 1

I hope it helps!

5 0

3 years ago

How many atoms are in 8.28 moles of aluminum?

Lilit [14]

Answer:

49.86 × 10²³ atoms of Al

Explanation:

Given data:

Number of moles of Al = 8.28 mol

Number of atoms = ?

Solution:

The given problem will solve by using Avogadro number.

It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.

The number 6.022 × 10²³ is called Avogadro number.

For example,

18 g of water = 1 mole = 6.022 × 10²³ molecules of water

1.008 g of hydrogen = 1 mole = 6.022 × 10²³ atoms of hydrogen

For 8.28 moles of Al:

1 mole = 6.022 × 10²³ atoms of Al

8.28 mol×6.022 × 10²³ atoms / 1mol

49.86 × 10²³ atoms of Al

4 0

3 years ago