How many electrons are present in 4He2+?

What molecule is responsible for chemical digestion.

padilas [110]

Answer:

Amylase.

Explanation:

The process of digestion begin to start in mouth when food mix with saliva. An enzyme is released which is called Amylase help in digestion of carbohydrates.

8 0

3 years ago

A 35.0 ml sample of 0.225 m hbr was titrated with 42.3 ml of koh. What is the concentration of the koh?

Lemur [1.5K]

Answer:

The concentration of KOH is 0.186 M

Explanation:

First things first, we need too write out the balanced equation between HBr and KOH.

This is given as;

KOH (aq) + HBr (aq) → KBr (aq) + H2O (l)

From the reaction above, we can tell that it takes 1 mole of KOH to react with 1 mole of HBr.

We use the acid base formular in calculating unknown concentrations. This is given as;

$\frac{CaVa}{CbVb} = \frac{na}{nb}$

where;

Ca = Concentration of acid

Va = Volume of acid

Cb = Concentration of base

Vb = Volume of base

na = Number of moles of acid

nb = Number of moles of base

KOH is the base and HBr is acid.

Hence;

Ca = 0.225

Va = 35

Cb = ?

Vb = 42.3

na = 1

nb = 1

Making Cb subject of formular we have;

$Cb = \frac{CaVaNb}{VbNa}$

Cb = (0.225 * 35 * 1) / (42.3 * 1)

Cb = 0.186 M

5 0

3 years ago

If a 1.00 mL sample of the reaction mixture for the equilibrium constant experiment required 32.40 mL of 0.258 M NaOH to titrate

andrey2020 [161]

Answer:

The concentration of acetic acid is 8.36 M

Explanation:

Step 1: Data given

Volume of acetic acid = 1.00 mL = 0.001 L

Volume of NaOH = 32.40 mL = 0.03240 L

Molarity of NaOH = 0.258 M

Step 2: The balanced equation

CH3COOH + NaOH → CH3COONa + H2O

Step 3: Calculate the concentration of the acetic acid

b*Ca*Va = a*Cb*Vb

⇒with b = the coefficient of NaOH = 1

⇒with Ca = the concentration of CH3COOH = TO BE DETERMINED

⇒with Va = the volume of CH3COOH = 1.00 mL = 0.001L

⇒with a = the coefficient of CH3COOH = 1

⇒with Cb = the concentration of NaOH = 0.258 M

⇒with Vb = the volume of NaOH = 32.40 mL = 0.03240 L

Ca * 0.001 L = 0.258 * 0.03240

Ca = 8.36 M

The concentration of acetic acid is 8.36 M

6 0

3 years ago

PLEASE HELP

alukav5142 [94]

Answer:

will form bonds between atoms. for more details are in the pic

7 0

3 years ago

Calculate δ h for the reaction:no (g) + o2 (g) ↔ no2 (g). given: 2o3(g) ↔ 3o2(g) δh=-426 kj o2(g) ↔ 2o(g) δh=+ 490 kj no(g) + o3

maks197457 [2]

To calculate the δ h, we must balance first the reaction:

NO + 0.5O2 -----> NO2

Then we write all the reactions,

2O3 -----> 3O2 δ h = -426 kj eq. (1)

O2 -----> 2O δ h = 490 kj eq. (2)

NO + O3 -----> NO2 + O2 δ h = -200 kj eq. (3)

We divide eq. (1) by 2, we get

O3 -----> 1.5O2 δ h = -213 kj eq. (4)

Then, we subtract eq. (3) by eq. (4)

NO + O3 -----> NO2 + O2 δ h = -200 kj
- (O3 -----> 1.5 O2 δ h = -213 kj)
NO -----> NO2 - 0.5O2 δ h = 13 kj eq. (5)

eq. (2) divided by -2. (Note: Dividing or multiplying by negative number reverses the reaction)

O -----> 0.5O2 δ h = -245 kj eq. (6)

Add eq. (6) to eq. (5), we get

NO -----> NO2 - 0.5O2 δ h = 13 kj
+ O -----> 0.5O2 δ h = -245 kj
NO + O ----> NO2 δ h = -232 kj

ANSWER: NO + O ----> NO2 δ h = -232 kj

4 0

3 years ago