How many neutrons does an element have if its atomic number is 40 and its mass number is 154

An Erlenmeyer flask contains 25.00 mL of 0.10 M HCl. What is the pH of the solution?

max2010maxim [7]

C=0.10 mol/l

pH=-lg[H⁺]

HCl = H⁺ + Cl⁻

pH=-lgc

pH=-lg0.10=1.0

pH=1.0

4 0

3 years ago

Read 2 more answers

AIDS is one disease caused by a virus infection. The virus attacks immune system cells known as T cells.

VLD [36.1K]

Answer:

yes,its true

Explanation:

I just want to say first off

the immune cell known as T cell also known as white blood cells

Since the first main attack from the bodies response against a virus is deploying T cells to attack

CD4 cells are the basic T cells and HIV virus which is AIDS will start to "Eat itself inside" Ofc not they will use protein spikes to form their way in

they start to create copies of themselves inside the T cell itself and creating a new protein called Env to form their ways in ofc

They are able to bypass CD4 cells is because its a basic cellular receptor for T cells making them really deadly

They now will start to attack other white cells and deploying more and more of their virus cells

7 0

3 years ago

Calculate the standard emf for the following reaction:

krek1111 [17]

In order to solve this, we need to know the standard cell potentials of the half reaction from the given overall reaction.
The half reactions with their standard cell potentials are:
<span>2ClO−3(aq) + 12H+(aq) + 10e- = Cl2(g) + 6H2O(l)
</span><span>E = +1.47
</span>
<span>Br(l) + 2e- = 2Br-
</span><span>E = +1.065
</span>
We solve for the standard emf by subtracting the standard emf of the oxidation from the reducation, so:
1.47 - 1.065 = 0.405 V

4 0

3 years ago

If excess ammonium sulfate reacts with 20.0g of calcium hydroxide how many grams of ammonia are produced

bagirrra123 [75]

The reaction between ammonium sulfate and calcium hydroxide is given below.
(NH₄)₂SO₄ + Ca(OH)₂ --> 2NH₃ + CaSO₄ + 2H₂O
From the balance equation, we can conclude that every 74 g of calcium sulfate reacted with enough amount of ammonium sulfate will yield 34 grams of ammonia. From the given amount,
(20 g calcium sulfate) x (34 grams ammonia / 74 g calcium sulfate)
= <em>9.19 g ammonia</em>

3 0

3 years ago

8.0 mol AgNO3 reacts with 5.0 mol Zn in

Yakvenalex [24]

Taking into account the reaction stoichiometry, 8 moles of Ag can be produced from 8 moles of AgNO₃ and 5 moles of Zn.

<h3>Reaction stoichiometry</h3>

In first place, the balanced reaction is:

2 AgNO₃ + Zn → 2 Ag + Zn(NO₃)₂

By reaction stoichiometry (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of moles of each compound participate in the reaction:

AgNO₃: 2 moles
Zn: 1 mole
Ag: 2 moles
Zn(NO₃)₂: 1 mole

<h3>Limiting reagent</h3>

The limiting reagent is one that is consumed first in its entirety, determining the amount of product in the reaction. When the limiting reagent is finished, the chemical reaction will stop.

<h3>Limiting reagent in this case</h3>

To determine the limiting reagent, it is possible to use a simple rule of three as follows: if by stoichiometry 1 mole of Zn reacts with 2 moles of AgNO₃, 5 moles of Zn reacts with how many moles of AgNO₃?

$amount of moles of AgNO_{3}= \frac{5 moles of Znx2 moles of AgNO_{3}}{1 mole of Zn}$

<u><em>amount of moles of AgNO₃= 10 moles </em></u>

But 10 moles of AgNO₃ are not available, 8 moles are available. Since you have less moles than you need to react with 5 moles of Zn, AgNO₃ will be the limiting reagent.

<h3>Moles of Ag formed</h3>

Considering the limiting reagent, the following rule of three can be applied: if by reaction stoichiometry 2 moles of AgNO₃ form 2 moles of Ag, 8 moles of AgNO₃ form how many moles of Ag?

$amount of moles of Ag=\frac{8 moles of AgNO_{3}x2 moles of Ag }{2 moles of AgNO_{3}}$

<u><em>amount of moles of Ag= 8 moles</em></u>

Then, 8 moles of Ag can be produced from 8 moles of AgNO₃ and 5 moles of Zn.

Learn more about the reaction stoichiometry:

<u>brainly.com/question/24741074</u>

<u>brainly.com/question/24653699</u>

#SPJ1

4 0

1 year ago