All categories

3 years ago

What do scientists do during data collection?

Chemistry

2 answers:

Shkiper50 [21]3 years ago

5 0

Answer:

Explanation:

When they are collecting data, it means they are gathering info. This would be B.

Len [333]3 years ago

3 0

B. Gather information during an experiment

You might be interested in

What is the density of a board dimensions are 5.54 cm x 10.6 cm X 199 cm and whose mass is 28.6kg

exis [7]

Answer:

$d=2.44\ g/cm^3$

Explanation:

Given that,

The dimensions of the board is 5.54 cm x 10.6 cm X 199 cm.

The mass of the board is 28.6 kg.

Since, 1 kg = 1000 grams

28.6 kg = 28.6 × 1000 g = 28600 grams

Density = mass/volume

So,

$d=\dfrac{28600\ g}{(5.54\times 10.6\times 199)\ cm^3}\\\\d=2.44\ g/cm^3$

So, the density of a board is $2.44\ g/cm^3$ .

4 0

3 years ago

How many moles are there in 1.09 kg of Al(OH)3?

alina1380 [7]

question 1
moles = mass/molar mass of Al(OH)3
convert Kg to g
that is 1.09 x 1000=1090g

moles is therefore=1090g/78(molar mass of Al(OH)3)= 13.974 moles

question 2
moles=2.55g/327.2(molar mass of Pb(CO3)2= 7.79 x 10^-3 moles
from avogadro constant
1moles=6.02 x10^23 formula units
what about 7.79 x 10 ^-3
={(7.79 x 10^-3)moles x ( 6.02 x10^23)} /1 mole=4.69 x10^21 formula units

4 0

3 years ago

Which of the following is not a racquet sport?

Yanka [14]

The answer is b.volleyball

8 0

3 years ago

Read 2 more answers

Suppose you wanted to make a buffer of exactly ph 7.00 using kh2po4 and na2hpo4. if the final solution was 0.10 m in kh2po4, wha

OleMash [197]

Answer:- 0.138 M

Solution:- The buffer pH is calculated using Handerson equation:

$pH=pKa+log(\frac{base}{acid})$

$KH_2PO_4$ acts as a weak acid and $Na_2HPO_4$ as a base which is pretty conjugate base of the weak acid we have.

The acid hase two protons(hydrogen) where as the base has only one proton. So, we could write the equation as:

$H_2PO_4^-\rightleftharpoons H^++HPO_4^-^2$

Phosphoric acid gives protons in three steps. So, the above equation is the second step as the acid has only two protons and the base has one proton.

So, we will use the second pKa value. The acid concentration is given as 0.10 M and we are asked to calculate the concentration of the base to make a buffer of exactly pH 7.00.

Let's plug in the values in the equation:

$7.00=6.86+log(\frac{base}{0.10})$

$7.00-6.86=log(\frac{base}{0.10})$

$0.14=log(\frac{base}{0.10})$

Taking antilog:

$10^0^.^1^4=\frac{base}{0.10}$

$1.38=\frac{base}{0.10}$

On cross multiply:

[base] = 1.38(0.10)

[base] = 0.138

So, the concentration of the base that is $Na_2HPO_4$ required to make the buffer is 0.138M.

5 0

3 years ago

A scientist would build a model to observe what

allochka39001 [22]

Answer:

In science, a model is a representation of an idea, an object or even a process or a system that is used to describe and explain phenomena that cannot be experienced directly. Models are central to what scientists do, both in their research as well as when communicating their explanations.

3 0

3 years ago