All categories

2 years ago

A student measures the pH of a solution to be 6.8. Which should the student add if she wants to decrease the pH of the solution?

2 answers:

7 0

The neutral pH is 7. Less than 7 indicates an acid and more than 7 indicates a base (up to 14).
<span> NaCl - it's a salt (we can't measure the pH)
H2O - it can be an acid but also a base (the pH it is almost neutral,meaning close to 7 )
HF - it is a strong acid
</span><span> KOH - it is a strong base (pH=14)
</span>
↓

He needs to use HF (Hydrogen fluoride) to decrease the pH.

vichka [17]2 years ago

5 0

HF is the answer because it is an acid so it decreases overall ph. Did you understand?

You might be interested in

Obi Wan uses his Jedi mind tricks to compel people to do his will. The words he uses begin in his vocal cords which _____ the ai

lutik1710 [3]

I believe it is vibrate

7 0

3 years ago

Read 2 more answers

A certain water wave has a wavelength of 25 m and a frequency of 4.0 Hz. What is its velocity?

babymother [125]

Wave speed = frequency * wavelength
Wave speed = 4 * 25
Wave speed = 100 m/s

8 0

2 years ago

Rachel hits a golf ball into the air. What type of motion is the ball's path?

sladkih [1.3K]

Answer:

omg

the ground is BREAKING

Explanation:

5 0

2 years ago

Initial velocity vector vA has a magnitude of 3.00 meters per second and points 20.0o north of east, while final velocity vector

garri49 [273]

Answer:

$5.2\ \text{m/s}$

$70^{\circ}$ south of east

Explanation:

$v_a$ = 3 m/s

$\theta_a$ = $20^{\circ}$ north of east

$v_b$ = 6 m/s

$\theta_b$ = $40^{\circ}$ south of east = $360-40=320^{\circ}$ north of east

x and y component of $v_a$

$v_{ax}=v_a\cos \theta\\\Rightarrow v_{ax}=3\times \cos 20^{\circ}\\\Rightarrow v_{ax}=2.82\ \text{m/s}$

$v_{ay}=v_a\sin\theta\\\Rightarrow v_{ay}=3\times \sin20^{\circ}\\\Rightarrow v_{ay}=1.03\ \text{m/s}$

x and y component of $v_b$

$v_{bx}=v_b\cos \theta\\\Rightarrow v_{bx}=6\times \cos 320^{\circ}\\\Rightarrow v_{bx}=4.6\ \text{m/s}$

$v_{by}=v_b\sin\theta\\\Rightarrow v_{by}=6\times \sin320^{\circ}\\\Rightarrow v_{by}=-3.86\ \text{m/s}$

$\Delta v=v_b-v_a\\\Rightarrow \Delta v=(4.6-2.82)\hat{i}+(-3.86-1.03)\hat{j}\\\Rightarrow \Delta v=1.78\hat[i}-4.89\hat{j}$

Magnitude

$|\Delta v|=\sqrt{(-4.89)^2+1.78^2}\\\Rightarrow \Delta v=5.2\ \text{m/s}$

Direction

$\theta=\tan{-1}|\dfrac{-4.89}{1.78}|\\\Rightarrow \theta=70^{\circ}$

The magnitude of the change in velocity vector is $5.2\ \text{m/s}$ and the direction is $70^{\circ}$ south of east.

6 0

2 years ago

ArbitrLikvidat [17]

Answer:

D) Number of electrons.

Explanation:

Elements in the same group on the periodic table has the same number of electrons. These electrons are those involved in bonding with other atoms to form compounds.

3 0

2 years ago