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3 years ago

Please give me a clear message on what to do. how do you change your brainly username?

Chemistry

2 answers:

emmainna [20.7K]3 years ago

5 0

Answer:

you can't change it mate I am so sorry

BTW can you help me in my latest questions it's not related to studies it's a problem I am having with my laptop that need to get cured as I have exam tomorrow

iren2701 [21]3 years ago

5 0

Answer:

Follow these steps to make a change:

1) Log in to your account.

2) Go into Profile Settings, select Edit Profile.

3) Go to Your Preferences and edit the First Name section.

4) Select Change to save.

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What is the acceleration of a 45 kg mass pushed with 15 N of force?

belka [17]

Explanation:

F=ma

15=45a

15÷45=45a÷45

a=0.33m/s^2

6 0

4 years ago

Calculate the pH for the following weak acid. A solution of HCOOH has 0.12M HCOOH at equilibrium. The Ka for HCOOH is 1.8×10−4.

Shtirlitz [24]

Answer:

the pH of HCOOH solution is 2.33

Explanation:

The ionization equation for the given acid is written as:

$HCOOH\leftrightarrow H^++HCOO^-$

Let's say the initial concentration of the acid is c and the change in concentration x.

Then, equilibrium concentration of acid = (c-x)

and the equilibrium concentration for each of the product would be x

Equilibrium expression for the above equation would be:

$\Ka= \frac{[H^+][HCOO^-]}{[HCOOH]}$

$1.8*10^-^4=\frac{x^2}{c-x}$

From given info, equilibrium concentration of the acid is 0.12

So, (c-x) = 0.12

hence,

$1.8*10^-^4=\frac{x^2}{0.12}$

Let's solve this for x. Multiply both sides by 0.12

$2.16*10^-^5=x^2$

taking square root to both sides:

$x=0.00465$

Now, we have got the concentration of $[H^+] .$

$[H^+] = 0.00465 M$

We know that, $pH=-log[H^+]$

pH = -log(0.00465)

pH = 2.33

Hence, the pH of HCOOH solution is 2.33.

7 0

3 years ago

Read 2 more answers

What is the formula for triphosphorus tetrasulfide?

sladkih [1.3K]

Answer:

P3S4

Explanation:

hope this helps

3 0

3 years ago

An object has a mass of 15.2 g and a volume of 8.9 mL. <br> What is the density of the object?

Murljashka [212]

Answer:

recordando también que ** 1mL = 1cm ^ 3 **

(como ** 1 dm ^ 3 = 1 L **)

8 0

3 years ago

How many grams of O2(g) are needed to completely burn 73.7 g of C3H8(g)?

Inessa [10]

The balanced chemical reaction is:

C3H8 + 5O2 = 3CO2 + 4H2O

We are given the amount of C3H8 to be used for the reaction. This will be the starting point for the calculations.

73.7 g C3H8 (1 mol C3H8 / 44.11 g C3H8) ( 5 mol O2 / 1 mol C3H8 ) ( 32 g O2 / 1 mol O2 ) = 267.3 g O2

5 0

4 years ago