What is the formula for the aqueous salt produced when hydrofluoric acid is neutralized by sodium hydroxide?

By making several measurements with the same balance, a chemist obtained values of 5.224 g, 5.235 g, and 5.259 g for the mass of

stepan [7]

Answer:

a) Measurements have a good precision.

Explanation:

Accuracy is the proximity of the data to the value considered as real, in this situation we do not know the real value and we do not know if the data is accurate or not, so we can discard options b and d.

Now, precision is the proximity of the data obtained among themselves and that is what we can observe, so the appropriate answer is the option a.

6 0

3 years ago

A certain reaction has an activation energy of 25.88 kJ/mol. At what Kelvin temperature will the reaction proceed 6.00 times fas

Juli2301 [7.4K]

Answer:hi

Explanation:

5 0

2 years ago

Question 2 (0 points)

bazaltina [42]

Answer:

The probability of spinning red with the spinner or rolling an odd number with the die is $\dfrac{1}{8}$

Explanation:

Given that,

Total color in spinner = 4

Let the area of four parts is equal in the spinner.

We need to calculate the probability of spinning red

Using formula of probability

$P(A) = \dfrac{Number\ of\ red\ color\ outcome}{Total\ number\ of\ colors\ in\ the\ spinner}$

Put the value into the formula

$P(A)=\dfrac{1}{4}$

We need to calculate the probability of odd number of the die

Using formula of probability

$P(B) = \dfrac{Number\ of\ odd\ digits\ outcome}{Total\ number\ of\ digits\ in\ the\ die}$

Put the value into the formula

$P(B)=\dfrac{3}{6}$

$P(B)=\dfrac{1}{2}$

We need to calculate the probability of spinning red with the spinner or rolling an odd number with the die

Using formula of probability of two events which is independent

$P(A\ and\ B)=P(A)\times P(B)$

Put the value into the formula

$P(A\ and\ B)=\dfrac{1}{4}\times\dfrac{1}{2}$

$P(A\ and\ B)=\dfrac{1}{8}$

Hence, The probability of spinning red with the spinner or rolling an odd number with the die is $\dfrac{1}{8}$

5 0

2 years ago

What is the pressure in millimeters of mercury of 0.0130 molmol of helium gas with a volume of 210. mLmL at 55 ∘C∘C? (Hint: You

juin [17]

Answer : The pressure of the helium gas is, 1269.2 mmHg

Explanation :

To calculate the pressure of the gas we are using ideal gas equation:

$PV=nRT$

where,

P = Pressure of $He$ gas = ?

V = Volume of $He$ gas = 210. mL = 0.210 L (1 L = 1000 mL)

n = number of moles $He$ = 0.0130 mole

R = Gas constant = $0.0821L.atm/mol.K$

T = Temperature of $He$ gas = $55^oC=273+55=328K$

Putting values in above equation, we get:

$P\times 0.210L=0.0130mole\times (0.0821L.atm/mol.K)\times 328K$

$P=1.67atm=1269.2mmHg$

Conversion used : (1 atm = 760 mmHg)

Thus, the pressure of the helium gas is, 1269.2 mmHg

4 0

2 years ago

The graph given below shows the motion of four runners P, Q, R, and S in a 5 km marathon.

wel

Answer:-

As we can see from the graphical data,

The distance covered by all the four runners is the same 5 km.

Among the four athletes, Athlete P covers the distance in under three hours.

It is the minimum time taken among the four athletes.

Thus Athlete P covers the 5 km distance in the minimum amount of time.

We know that speed = $\frac{Distance}{Time}$

Since time taken for P is minimum, his speed is the maximum. P ran the fastest.

Time taken by Q = 4.5 hours.

Speed of Q = $\frac{Distance}{Time taken by Q}$

= $\frac{5km}{4.5hour}$

= 1.1 km/ hr

Time taken by R = 6 hours.

Speed of R = $\frac{Distance}{Time taken by R}$

= $\frac{5km}{6hour}$

= 0.8 km/ hr

3 0

3 years ago