PT: \(Fe+2HCl\rightarrow FeCl_2+H_2\)

Ta có: \(n_{H_2}=\dfrac{20}{24,79}\left(mol\right)\)

Theo PT: \(n_{HCl}=2n_{H_2}=\dfrac{40}{24,79}\left(mol\right)\)

\(\Rightarrow C_{M_{HCl}}=\dfrac{\dfrac{40}{24,79}}{0,5}\approx3,23\left(M\right)\)

(d) cắt Ox nên ta có phương trình hoành độ:

    (k - 1)\(x\) - 4 = 0

     (k - 1)\(x\)        = 4

               \(x\)       = \(\dfrac{4}{k-1}\) (k ≠ 1)

Theo bài ra ta có:

                 \(\dfrac{4}{k-1}\) ≤ 1

       ⇒      \(\dfrac{4}{k-1}\) - 1 ≤ 0

                 \(\dfrac{4-k-1}{k-1}\) ≤ 0

                  \(\dfrac{5-k}{k-1}\) ≤ 0

                   A = \(\dfrac{5-k}{k-1}\) ≤ 0

 Lập bảng ta có: 

Theo bảng trên ta có: 1 < k hoặc k ≥ 5

Kl:...

y x 7,5 + y + y x 91,4 + y : 10 = 257,8

y x 7,5 + y x 1 + y x 91,4 + y x 0,1 = 257,8

y x (7,5 + 1 + 91,4 + 0,1) = 257,8

y x 100 = 257,8

y = 257,8 : 100

y = 2,578

-Vôi tôi tôi tôi là vôi của tôi do chính tay tôi pha nên đó là vôi của tôi

-Đầu gối đầu gối là đầu gối và cái đầu gối của mik

Cho mik 1 like nhé

275022+54565855454115999947=?

5x5-5=20

5:5x5=5

5:5x5:5x5x5=25

5 x 5 - 5 = 20

5 + 5 - 5 = 5

5 x 5 + 5 - 5 + 5 - 5 = 25

1.        From: Jenny

       To: Eric

       Subject: About my family members

       Hi Eric,

       Long time no see you. How are you? How about the first exam you did at school?

     Tet holiday is the biggest and the most important festival in VietNam. Tet often falls between late January and early February. Before Tet, my mother and I go shopping to buy clothes, candies, flowers, fruits and decorative items. My family always cleans and decorates our house together. On the first day of Tet, I don’t go out, I stay at home and sit around the pot of Banh Chung to talk, watch fireworks with my family. On the second day, I go to my grandparents’s house with my family and they give me lucky money. It’s always a nice day because I like to meet my grandparents so much! Next, on the third day, I visit my teachers and send them New Year wishes. And my favorite most is get the lucky money from the older because it brings me lucks in the year! How do you fell about Tet? Write me soon!

      Best,

       Jenny

TICK VÀ LIKE CHO MÌNH NHA MÌNH CẢM ƠN. THANKS