Answer:
0.3M
Explanation:
Step 1:
Data obtained from the question. This include the followingb:
Volume of acid (Va) = 90mL
Concentration of acid (Ca) = 0.2M
Volume of base (Vb) = 60mL
Concentration of base (Cb) =....?
Step 2:
The balanced equation for the reaction. This is given below:
HBr + NaOH —> NaBr + H2O
From the balanced equation above,
The mole ratio of the acid (nA) = 1
The mole ratio of the base (nB) = 1
Step 3:
Determination of the concentration of the base, NaOH.
The concentration of the base can be obtained as follow:
CaVa /CbVb = nA/nB
0.2 x 90 / Cb x 60 = 1
Cross multiply
Cb x 60 = 0.2 x 90
Divide both side by 60
Cb = 0.2 x 90 /60
Cb = 0.3M
Therefore, the concentration of the base, NaOH is 0.3M
Answer:
The method is accurate in the calculation of the 
Explanation:
As a first step we have to calculate the <u>average concentration </u>of find it by the method.
Then we have to find the<u> standard deviation:</u>
For the confidence interval we have to use the formula:
μ=Average±
Where:
t=t student constant with 95 % of confidence and 5 data=2.78
μ= 
± 
upper limit: 0.84
lower limit: 0.75
If we compare the limits of the value obtanied by the method (Figure 1 Red line) with the reference material (Figure 1 blue line) we can see that the values obtained by the method are within the values suggested by the reference material. So, it's method is accurate.
Explanation:
Pineapple juice often shows an unstable cloud and produces a solid precipitate that is not very attractive for consumers. Cloud stabilization by pectin addition is permitted by EU and Codex standards to counteract this effect. This additive must be labeled and its content should not exceed fixed maximum standards (Website of AIJN Code of Practice). Determination of water-soluble pectins by IFU method 26 (Website of International Fruit and Vegetable Juice Association) can be used for control of this parameter. Pectin addition to pineapple juice or juice concentrate, etc. may also be detected after its isolation by 13C isotopic analysis (Hammond, 2006) as explained later.
Answer:
0.2257kg
Explanation:
Using the formula density= mass/ volume
- density=22.57g/cm³
- volume=1*4*2.5cm³= 10cm³
- mass is unknown
22.57g/cm³=mass/10cm³
mass = 22.57g/cm³*10cm
=225.7g
but in kg
= 0.2257kg
